Bax∆2 is a pro-apoptotic anti-tumor protein in the Bax family. While most of the Bax family causes cell death by targeting mitochondria, Bax∆2 forms cytosolic aggregates and activates caspase 8-dependent cell death. We previously showed that the Bax∆2 helix α9 is critical for caspase 8 recruitment. However, the interaction between these two proteins at the structural level is unknown. In this in silico study, we performed molecular dynamics (MD) simulations and protein–protein docking on Bax∆2 variants. The results suggest that the Bax∆2 variants have different stable states. Mutating the Baxα mitochondria-targeting signal [L26P/L27P] appears to introduce a kink into helix α1. Protein–protein docking suggests that helices α9 of both wild-type Bax∆2 and Bax∆2 caspase 8 binding-deficient mutant [L164P] can fit in the same caspase 8 binding site, but the mutant is unable to fit as well as wild-type Bax∆2. Together, these data point to a structural basis for explaining Bax∆2 function in caspase 8-dependent cell death. Programmed cell death, also called apoptosis, plays a fundamental role in both physiological and pathological processes such as development, tumorigenesis and neurodegeneration ,2. ApoptBax is well-known to be a key component in the intrinsic apoptotic pathway and is ubiquitously expressed in almost all human organs . The rolBax∆2 is an isoform of the Bax family and a potential target for cancer drugs . CompareIn addition to its potential benefits in cancer treatment, Bax∆2 is also compelling because, unlike its relatives in the Bax family, it is not involved in the intrinsic apoptotic pathway, but actually activates the extrinsic pathway ,21,22. LThe contrasting cellular behaviors of Bax variants led us to wonder whether they have distinct structures. Previously, we had predicted protein secondary structure changes with the Netsuvfp server . In thesIn the present contribution, we report modeling at the level of tertiary structure. Although the structure of Baxα has been extensively studied, no structures of Bax∆2 are publicly available. To provide a structural basis for the behavior of Bax∆2, we built models of four Bax variants that were characterized in our previous paper : wild-tyDue to the helix deletion, we thought Bax∆2 would have a different structure from Baxα variants. However, structures of Bax variants predicted by the RaptorX server were all very similar to one another; this result is probably due to the models being based on the same templates. For example, the predicted structure of Baxα is very similar to its crystal structure . Over thRepresentative configurations from the MD simulations provide greater detail about the structural predictions B. ExceptPredicted structural differences between Baxα and Baxα[L26P/L27P] are most evident in helix α1. Over the course of 200 ns of simulation, the RMSD of Baxα helix α1 is mostly within 2 Å of the initial structure. However, in two of three simulations, the RMSD of helix α1 in Baxα[L26P/L27P] dramatically increases within the first 20 ns A or 125 In contrast to the mutant [L26P/L27P], the predicted effects of the mutant [L164P] are less straightforward. The most intuitive explanation of the effects of L164 would be that the mutant disrupts helix α9, interfering with the ability of Bax∆2 to recruit caspase 8. However, the RMSD of helix α9 converges to within 3 Å for all the Baxα and Bax∆2 variants . The helThe perturbation of helix α2 is predicted to occur through an indirect mechanism. The Bax∆2[L164P] mutant has a smaller side chain, allowing Y98 to move toward helix α9 A,B. ThisProtein–protein docking predicts a direct physical interaction between Bax∆2, Bax∆2[L164P] and the caspase 8 DED. Although Bax∆2 and Bax∆2[L164P] were allowed to dock in any orientation, the lowest-energy docking poses feature an interaction between helix α9 and the DED A.The calculations are consistent with the experimental observation that Bax∆2[L164P] is unable to mediate caspase 8-dependent apoptosis. The docking score of Bax∆2, −32.982 REU (Rosetta energy units), is lower than the score of Bax∆2[L164P], −29.307 REU, indicating a stronger binding affinity. Hydrogen bonds contribute to the difference in scores. Bax∆2 is predicted to form two hydrogen bonds with the caspase 8 DED: Bax∆2 Q154 with DED E116 (2.191 Å) and Bax∆2 T155 with DED S119 (1.572Å) B. HoweveA possible reason that Bax∆2[L164P] does not dock as well as Bax∆2 to the caspase 8 DED is the inability to find the same low-energy pose during the docking calculation. To test whether the binding pose of Bax∆2 bound to the caspase 8 DED was suitable for binding Bax∆2[L164P], we superposed the Bax∆2[L164P] structure with the lowest docking score onto the structure of Bax∆2 in the predicted complex. This superposition leads to steric clashes between three residues, N89, T155, F159, on Bax∆2[L164P] corresponding to E127, S119 and F120 on the caspase 8 DED , indicatThe relative populations of the representative snapshots also suggests that Bax∆2 is a stronger binder of the caspase 8 DED than its mutant. With Bax∆2, the snapshot with the lowest docking score for the caspase 8 DED is in a highly populated region in the 2D histogram of principal component analysis . On the Using MD simulations and protein–protein docking, we have unveiled details about the likely effect of mutations on the structure of Bax variants and their interactions with caspase 8. The calculations not only explain previous experimental results, but also provide insights that can help design future experiments.MD simulations support the prevailing hypothesis that helix α1 is essential for mitochondrial targeting ,16,21. ASimulations of Bax∆2 also provide structural models that can be used in the computer-aided design of chemical probes and drugs. Presently, no compounds are known to selectively bind to the Bax∆2 isoform. It is possible that ligands which bind Bax∆2 can inhibit its proteasomal degradation and activate apoptosis in cancer cells.Our modelling also provides a plausible structural mechanism for the interaction between Bax∆2 and caspase 8. Unlike most of the Bax family, Bax∆2 lacks helix α1 and is unable to target the mitochondria ,21,22. IThe new calculations suggest that there is a direct physical interaction between helix α9 of Bax∆2 and the caspase 8 DED. In particular, we propose a pair of hydrogen bonds between Bax∆2 Q154 and T155 with caspase 8 DED E116 and S119, respectively. The importance of E116 and S119 on caspase 8 is corroborated by its location on helix α2 of chain B. This helix has been shown to be important in the activation of caspase 8 by dimerization with the DISC . Bax∆2 mThe calculations suggest that our previously designed L164P mutation does not disrupt the structure of Bax∆2 in the most intuitive way. Previously, using protein secondary structure prediction based on NetSurfP 1.1  and GOR4While the MD simulations suggest that L164P disrupts the structure of Bax∆2 in a counterintuitive way, the subsequent protein–protein docking still supports the importance of helix α9. In Bax∆2, Q154 and T155 are located at the beginning of helix α9 and fit well into the “grove” between two helices of the caspase 8 DED. However, the structural perturbations of Bax∆2[L164P] helix α9, although more subtle than initially anticipated, render it unable to fit in the same way as wild-type Bax∆2.Considering both our calculations and previous experimental results, we propose that both helix α9 and an aggregate of sufficient size are necessary for the activation of caspase 8-mediated apoptosis by Bax variants . We haveAt this point, the anatomic properties of the Bax∆2 aggregates necessary to recruit caspase 8 remain unclear. Bax∆2 aggregates observed under a microscope after immunostaining vary in both size and shape. We are unable to determine the position of helix α9 in these aggregates. Based on the available crystal structures and our computational modeling, it appears that helix α9 is located on the surface of the protein in monomers of both Baxα and Bax∆2. For Baxα, upon a death signal stimulation, the monomers change conformation and organize into oligomers that anchor into the mitochondrial outer membrane via a barrel channel structure . In thisThe open reading frames from amino acid sequences of Baxα (AAA03619) and Bax∆2 (AFU81108) were obtained from the GenBank database . The amiInitial structural models for the four Bax variants were generated using RaptorX , a prote+ and Cl− ions were added to the system for neutralizing and modeling the 0.15 M physiological concentration. Each system was energy-minimized for 500 steps, and each MD simulation was performed in the NPT  ensemble and was propagated for 200 ns. The pressure was controlled by the Monte Carlo barostat at 1 atmosphere of pressure with moves every 25 time steps. Particle mesh Ewald (PME) was used to treat long-range nonbonded interactions. A Langevin dynamics integrator with a 2 fs time step was used, with a bath temperature of 300 K and constraints on bonds involving hydrogen. Energies and frames were recorded every 1 ps. The simulations were repeated three times for each variant.For each variant, MD simulations were performed using OpenMM 7.0 . ProteinPrody 1.8.2  and VisuSmoothing of time series was performed using the Savitzky–Golay filter implemented in the python package scipy 1.2.1 . The filPrincipal component analysis (PCA), a dimensionality reduction technique, was performed using scikit-learn decomposition 0.15.2 . First, Representative structures were selected by constructing a histogram of the first two principal components of each molecular dynamics trajectory. A structure was selected from near the mode of the 2D histogram.K-means clustering with 100 clusters was performed using scikit-learn 0.15.2 . Distanc


The significant positive correlation between the human developed index (HDI) developed by the United Nations Development Program, and fingernail δ13C at the county level proved to be useful as a new proxy in tracking human nutrition. Regions with higher HDI are those with higher consumption of highly processed food.High  These studies have demonstrated the progressive substitution of local food staples by industrialized processed foods in the developing regions of the world 3. In this context, we explored stable isotopic analysis as a new proxy for human nutrition status across Brazil under the worldwide “global supermarket” dietary trend. Brazil is a middle-income country with contrasting inequitable geographic regions in terms of socioeconomic development, health, and educational services4. We compared the carbon isotopic ratio of fingernails from residents of more economic developed regions of the country, where high consumption of processed food prevails, with the less developed regions, where locally produced food predominates, particularly staples like rice, beans, and cassava.Several studies have used the multi-isotope approach to track the geographic origin of human remains as well as human movement in forensic anthropology3 plants have δ13C varying approximately from −34 to −24‰, C4 plants have δ13C that varies from −14 to −10‰, with no overlap between these plant types5. Therefore, in recent decades, carbon isotopic composition became a useful tool to track C3 and C4 carbon in biological systems worldwide6. Despite the fact that pineapple that is a CAM plant that could confound a straightforward interpretation of C3 vs. C4 diet contribution5. its consumption has no significant impact in the Brazilian diet. In fact, fruits and vegetables provide approximately only 2% of total daily calories to Brazilians6.While C4 crops; among them, C4 pastures cover an area of almost 200 million ha4. Although soy occupies almost 35 million ha, corn is the second arable crop in the country covering almost 20 million ha, and sugarcane covering 10 million ha is the third. Due to these vast productive areas, C4 carbon sources in Brazil are generally an inexpensive alternative for the food industry either as sugar or high-fructose corn syrup. Accordingly, C4 carbon is available in the country in several energy-dense processed foods like dairy, various types of processed meats, beverages , cakes, crackers, and even unexpectedly, in products like soy sauce8.Brazil is mostly a tropical country with proper climatic conditions to grow Cδ13C in human tissues than residents of other countries10. However, in more isolated towns and villages in different geographic regions of Brazil where the degree of market integration is highly variable, the δ13C of human tissues reflects a diet based more on C3 plants , coupled with consumption of locally derived animal protein, such as fish or bushmeat, depending on the region11.This in part explains why Brazilians residing in urban areas have higher 12 reported a positive correlation between Human Development Index (HDI) and body weight at the state level in Brazil, our initial hypothesis was that at the county level, the HDI and fingernail δ13C representing county residents [δ13C]m would be positively correlated. In order to test this hypothesis, we correlated the HDI at the county level [HDI]m with the [δ13C]m (see “Methods” for definition) among 37 counties distributed in different geographic regions of Brazil :We found a strong positive sigmoidal correlation Fig.  between 12, confirming our initial hypothesis.In this sense, Eq.  suggestsδ13C]m was estimated for the 5507 Brazilian counties (see “Methods”), and with these values a map of [δ13C]m was generated in order to shed light on spatial trends for the country  was determined in fingernails of residents of 37 Brazilian counties totaling almost 4500 samples (Supplementary Table The carbon isotope ratio 3C:12C wa13C:12C) in these samples was determined through a Delta Plus mass spectrometer for isotopic ratios (ThermoFisher Scientific), in the Laboratory of Isotope Ecology, CENA (University of São Paulo), Brazil. The results were reported as the deviation (δ) in parts per thousand (‰) relative to standard international references; δX = (Rsample/Rstd − 1) × 1000; where, X is carbon, R is the heavy to light isotope ratio for carbon (13C:12C) of the sample (Rsample), and of the standard (Rstd), VPDB-Vienna Pee Dee Belemnite. BBOT (Fisons Instruments [C26H26N2O2S]) and “grounded leaves of sugarcane” were used as internal standards to calibration during analysis runs. Every ten runs, both internal standards were used as target sample. Long-term standard deviations of internal standards used at the Ecology Isotope laboratory are of 0.2‰ for carbon.The carbon isotopic ratio  was obtained by averaging the δ13C of all donors from a municipality.The fingernail 7. Details on sampling can be found in these publications. Not all samples were obtained in the same year, and this fact could be a limitation resulting in biased findings if temporal changes were large. However, most of the samples  were obtained from 2008 to 2015; 23% from 2002 to 2006; and 10% after 2015. Another important source of variability could be the fact that in some regions only urban centers were sampled, whereas in others, mainly in the Amazon region, small isolated villages were also included. This is important to mention because we have shown in other publications that urban centers are fully market integrated, and more isolated villages are not; these villages tend to have lower δ13C than urban centers in the same county7.The counties included in this study represent 0.7% of the 5,507 Brazilian counties, and ~10% of Brazil’s population (Supplementary Table http://hdr.undp.org/en/content/human-development-index-hdi). Brazil was the first country to launch HDI at the municipality level ([HDI]m) using basically the same parameters of the HDI developed by the United Nations. We obtained HDI at the municipality level [HDI]m for 2010, the last available year for Brazilian counties (http://www.atlasbrasil.org.br).The HDI was created in 1990 by the United Nations as a response to persistent criticism throughout the 1980s that economic development alone could not capture human development . The Boltzmann sigmoidal equation used in the present work was:δ13C values close to C4 crops, could show a false positive correlation between δ13C of human tissues and consumption of meats and processed food. However, due to its high price, seafood consumption in Brazil is rather low, even in coastal cities as well as in marine fishing villages.14High consumption of seafood, with Supplemental Material


However, current evidence in these indications is limited. A European ECCO2R Expert Round Table Meeting was convened to further explore the potential for this treatment approach.With recent advances in technology, patients with acute respiratory distress syndrome (ARDS) and severe acute exacerbations of chronic obstructive pulmonary disease (ae-COPD) could benefit from extracorporeal CO2R therapy is applied, identify how patients are selected and how treatment decisions are made, as well as to identify any points of consensus.A modified Delphi-based method was used to collate European experts’ views to better understand how ECCO2R or extracorporeal membrane oxygenation. ARDS was considered the primary indication for ECCO2R therapy (n = 7), while 3 participants considered ae-COPD the primary indication. The group agreed that the primary treatment goal of ECCO2R therapy in patients with ARDS was to apply ultra-protective lung ventilation via managing CO2 levels. Driving pressure (≥ 14 cmH2O) followed by plateau pressure  was considered the most important criteria for ECCO2R initiation. Key treatment targets for patients with ARDS undergoing ECCO2R included pH (> 7.30), respiratory rate (< 25 or < 20 breaths/min), driving pressure (< 14 cmH2O) and Pplat (< 25 cmH2O). In ae-COPD, there was consensus that, in patients at risk of non-invasive ventilation (NIV) failure, no decrease in PaCO2 and no decrease in respiratory rate were key criteria for initiating ECCO2R therapy. Key treatment targets in ae-COPD were patient comfort, pH (> 7.30–7.35), respiratory rate (< 20–25 breaths/min), decrease of PaCO2 (by 10–20%), weaning from NIV, decrease in HCO3− and maintaining haemodynamic stability. Consensus was reached on weaning protocols for both indications. Anticoagulation with intravenous unfractionated heparin was the strategy preferred by the group.Fourteen participants were selected based on known clinical expertise in critical care and in providing respiratory support with ECCO2R therapy may be an effective supportive treatment for adults with ARDS or ae-COPD. Further evidence from randomised clinical trials and/or high-quality prospective studies is needed to better guide decision making.Insights from this group of experienced physicians suggest that ECCO For initiating ECCO2R therapy in patients with ARDS, driving pressure (≥ 14 cmH2O) followed by Pplat (≥ 25 cmH2O) was considered the most important criteria, and this was confirmed in the post-meeting survey , respiratory rate (≥ 25 to > 30 breaths/min), PaO2/FiO2 (100–200) and PEEP (combined findings from Rounds 2 and 3).There was consensus among the group , or to facilitate UPLV to prevent the deleterious effects of MV in patients already undergoing LPV (n = 7). Based on the results of the post-meeting survey, a consensus was reached among the group  that ECCO2R was a strategy they would consider selecting for rescue in patients with ARDS. Typical characteristics for initiating ECCO2R in a rescue situation obtained as part of the post-meeting survey are summarised in Table 2R as a means of facilitating UPLV for patients with ARDS, and typical characteristics for selecting patients are summarised in Table Participants were evenly split during the meeting on the primary rationale for ECCO2R strategy if they met the indications for ECMO, such as severe or refractory ARDS ), PaCO2 (< 50 or < 55 mmHg) and VT (≤ 6 mL/kg PBW). Other target parameters were not proposed by the group (Table 2R therapy was suggested to be 1–3 days (n = 5) and 4–6 days (n = 9).The group considered treatment targets for their patients with ARDS undergoing ECCOessure < 4 cmH2O a2R in patients with ARDS, a protocol was proposed and reviewed as part of the post-meeting survey (Table n = 13) that this proposal was a suitable weaning strategy.Following discussion during the meeting on a protocol for weaning from ECCOey Table . The gro2R therapy were those at risk of NIV failure, as well as patients recently initiated on MV after NIV failure to allow for early extubation within 24 h of initiating ECCO2R therapy. Other patient groups would be considered (e.g. patients on prolonged MV who require weaning from invasive ventilation and patients who are refusing intubation), but a consensus was not reached.There was consensus during the meeting that patients with ae-COPD who should receive ECCO2’ and ‘no decrease in respiratory rate’ while on NIV were both key initiation criteria for ECCO2R therapy (Table n = 5] or 7.25–7.30 [n = 6]) would be considered as initiation criteria by most of the participants. Baseline PaCO2 and respiratory rate as main triggers were favoured by less than half of participants. For patients with ae-COPD who had already been intubated, criteria for initiating ECCO2R therapy varied ; contraindications to anticoagulation; problems with vascular access; patient’s wishes, e.g. refusal to be intubated, except in cases where ECCO2R therapy represented the last resource accepted by the patient; poor quality of life; and the patient not being a candidate for MV.Factors for excluding patients with ae-COPD from ECCO2R therapy were, in order of perceived importance . This was confirmed in the post-meeting survey, in which unfractionated heparin was the anticoagulant of choice for the majority (~ 90% of participants). The proposed heparin anticoagulation protocol agreed by the group is shown in Table Responses obtained during Round 1 (pre-meeting survey) showed that heparin was the preferred choice of anticoagulant used during ECCO2R therapy across Europe. During a typical Delphi process [2R therapy in patients with ARDS and ae-COPD, using a modified Delphi method may offer insight into the current practice of experienced users, which could help inform decision making in local clinical practice. Additionally, the use of the Delphi method to guide these discussions and reach points of consensus will be of potential benefit for the design of future trials. Specifically, the discussions provide insight relevant to inclusion criteria, guidance on the management of patients while receiving ECCO2R therapy and possible primary and secondary endpoints.The responses obtained from the Expert Round Table Meeting and accompanying pre- and post-meeting surveys have provided further insights into the use of ECCO process , 100% ag2R therapy in the treatment of patients with ARDS or ae-COPD were identified. There was consensus among the group that the primary treatment goal of ECCO2R therapy for patients with ARDS was to apply UPLV via managing CO2 levels; this is in agreement with the findings of a systematic literature review [2R therapy in patients with ARDS, driving pressure (≥ 14 cmH2O) followed by Pplat (≥ 25 cmH2O) was the most important criteria to consider. Higher PEEP, lower peak and plateau pressures and lower respiratory rate have been shown to correlate with improved survival in patients with ARDS [2R in ARDS identified by the group were reductions in driving pressure and respiratory rate.Key areas of consensus for the use of ECCOe review . The groith ARDS , 11, 31.ith ARDS . It is t2R therapy in this patient group. Indeed, a lower pH was recently shown to be independently associated with ICU mortality in the large prospective LUNG SAFE registry [2R should be initiated at PaCO2 levels > 60–80 mmHg. While it was suggested that permissive hypercapnia provided protection against lung injury in terms of lung permeability, oxygenation and lung mechanics [2 levels were considered important treatment targets, indicating that there is a perception that ECCO2R is an important therapy for the management of respiratory acidosis.A pH of < 7.25 was also considered by most of the group to be a criterion for initiation of ECCOregistry . Most ofechanics , more reechanics , 35. Rai2R therapy, either as a rescue therapy in patients with ARDS undergoing injurious MV, or to facilitate UPLV to prevent VILI. The results from the post-meeting survey highlighted that the group agreed that they would at least consider selecting ECCO2R as a strategy in both settings. Ongoing (NCT02654327) [2R, allowing UPLV in patients with acute hypoxemic respiratory failure.The experts were evenly split on the primary rationale for ECCO2654327)  randomis2R in patients with ARDS. The group reached a consensus regarding a strategy for weaning patients from ECCO2R in this setting. It was agreed that ECCO2R therapy should be applied for at least 48 h in patients with ARDS, and that a test for PaO2/FiO2 > 200 mmHg while maintaining a driving pressure < 14 cmH2O should be carried out to determine weaning possibility. It was also agreed that patients should be stable for a minimum of 12 h at the ventilation parameters outlined , REST (NCT02654327) [The insights from this group of experienced physicians suggested that ECCO2654327) , 12, 23 Additional file 1: Expanded methods. Details on the process for information gathering and the questions.


Various guidelines recommend that all adults diagnosed with type 1 diabetes (T1D) should be offered an evidence based, structured education programme (SEP) to optimize self-management care. China has a 13,000 annual increase in newly diagnosed T1D cases, of which 65% are adults. However, there is yet no validated SEP targeted to T1D patients in China. The purpose of this study is to establish a structured T1D self-management education programme—‘Type 1 Diabetes Education in Lifestyle and Self Adjustment’ (TELSA) that is adapted to medical and cultural practices in China.TELSA programme was developed based on the ADDIE model, following three steps: i) Semi-structured interviews were administered to 10 healthcare professionals (HCPs) and 13 T1D patients. Different topic guides, focusing on 4 dimensions including goals, contents, format of delivery, and quality assurance, were designed for either HCPs or patients. The interviews were recorded and analysed with thematic analysis. ii) Extracted themes were modified according to Delphi consultation. iii) Preliminary courses were conducted as pilot study to evaluate the effects of TELSA and optimization of the curriculum was finalized accordingly.A total of 18 themes in 4 dimensions of the programme design were identified in the final version: i) goals: ‘behaviour modification’ and ‘outcome improvement’; ii) contents: ‘living with T1D’, ‘self-monitoring of blood glucose’, ‘knowing insulin’, ‘insulin dose adjustment’, ‘carbohydrates and carbohydrate counting’, ‘hypoglycaemia’, ‘complications of diabetes’, ‘managing psychological issues’, ‘physical activity’, and ‘question-and-answer’; iii) format: ‘multidisciplinary team combined with peer support’, ‘face-to-face education followed by remote learning’, and ‘2-day programme held on weekends’; and iv) quality assurance: ‘after-class quiz’, ‘patients’ feedback’, and ‘long-term evaluation on effectiveness’.A type 1 diabetes structured education programme in China was set up and shown to be applicable under local medical, social, and cultural environment.NCT03610984. Date of registration: August 2, 2018. Type 1 diabetes (T1D) patients suffer from continuous loss of pancreatic β-cell function and need life-long exogenous insulin treatment. Adjusting insulin dose to keep glucose levels at target in a flexible daily routine remains an enormous challenge in T1D management. Diabetes self-management education (DSME) is critical for patients to achieve HbA1c targets, minimise hypoglycaemia, and optimise quality of life. Self-management training programmes such as dose adjustment for normal eating (DAFNE) and the diabetes teaching and treatment programmes (DTTP) have consistently demonstrated positive outcomes in diabetes control as well as quality of life in multiple studies . TherefoA recent study showed that China has 13,000 newly diagnosed T1D cases every year in spite of a low incidence rate , and is Due to lifestyle and social differences, SEPs should be tailored to each country. There is an urgent unmet need for a high-quality, standard T1D curriculum that empowers Chinese T1D patients with self-management skills and psychological support. Hence this study focused on establishing the ‘Type 1 Diabetes Education in Lifestyle and Self Adjustment’ (TELSA) programme, the first T1D SEP designed to match the medical, social, and cultural environment in China.The training programme was developed based on the ADDIE instructional design process –14. ThreA qualitative, descriptive design was adopted. Healthcare professionals (HCPs) certified for T1D clinical care and adult T1D patients (≥18 years of age) were recruited with purposive sampling strategy as interviewees. Patients with diabetes duration ≥3 months and no medical history of mental disorders or cognition impairment were recruited from 2 tertiary hospitals in Beijing and Changsha. HCPs who were certified for T1D clinical care and familiar with diabetes education programmes were selected from 4 tertiary hospitals in Beijing, Xi’an, Suzhou, and Changsha. All interviewees gave their informed consent. Interviews were conducted by a diabetes education nurse. Interview guidelines for either patients or HCPs  recognized experts in the field of T1D or diabetes education, ii) researchers with expertise in diabetes, education, or psychology, identified through literature review, and iii) researchers recommended through experts’ professional network. Purposive sampling was conducted. Ultimately, a multidisciplinary and geographically diverse group of 25 Chinese-based experts were invited in this Delphi panel . Participants’ basis of judgment and degree of familiarity for each item were also surveyed in this questionnaire. Free-text columns were included for collection of suggestions. Data were collated and re-presented to the research team for further refinement of TELSA. Here we defined a consensus regarding a specific item as at least 80% agreement (with Likert score 4–5) .‘I want to reduce the number of hypoglycaemic episode as well as incidences of very high blood sugar, and ultimately, to avoid complications.’[Patient (P) 1].‘What I hope is to be able to relieve my anxiety, and thus live a normal life.’[P9].HCPs in China will sometimes encounter T1D patients admitted with diabetic ketosis due to discontinuation of insulin therapy, because of invalidated treatments that can ‘cure’ T1D. Moreover, patients are frequently confused with different insulin categories and risk purchasing a wrong cartridge. Therefore, most HCPs recognized the importance of educating patients to achieve sufficient basic knowledge to avoid unnecessary cost.‘The most important goal of education is to reduce fundamental errors. For instance, some patients choose invalidated Chinese traditional medicine instead of insulin in the hope of curing T1D; some patients misuse NovoRapid 30 Mix as bolus instead of NovoRapid. These can be avoided through proper education right after diagnosis.’[H2].‘Through education, patients will have a correct understanding of diabetes self-management. … With various online resources that might be misleading, patients need easy access to professional educational materials that can teach correct from incorrect.’[H4].HCPs all agreed that the teaching session should start with a basic introduction to T1D.‘In the very beginning patients need to clearly understand what they are dealing with every day. … They should know, for example, what causes T1D, and what some of the most common misunderstandings of T1D are.’[H7].‘I think in the first class, it should be clarified what the benefits are for controlling diabetes. It should be pointed out that we can still have a normal life if diabetes is under control, so as to build our confidence.’[P2].‘… To help us correctly recognize ourselves: people who will be living with T1D life-long.’[P5].In addition to basic concepts, patients were generally more concerned about ‘to build a healthy attitude towards diabetes’ in the first place. 8 out of 13 patients mentioned an ice-breaking start with establishing their confidence to live with diabetes for the rest of their lives.The importance of SMBG has been greatly underestimated by most patients . Over 60‘I started with testing my blood glucose levels at least 7 times per day in the hope that I could figure out my glucose pattern. But soon I found it was a mission impossible. Then I just gave up and let it be. Now I just test randomly. As long as it is neither too high nor too low, I’m satisfied.’[P4].‘I’ve heard there is a way to check my blood glucose levels without finger prick. I’d like to know more about that.’[P10].‘In addition to the normal range, frequency, and correct procedures of testing blood glucose levels, the importance of SMBG should also be emphasized in different conditions, helping patients to form a habit of testing.’[H7].Patients’ negligence on SMBG is exactly why HCPs emphasize this topic. New techniques for glucose testing such as continuous glucose monitoring also need to be introduced.Almost all patients were stressed at different levels and occasions—stress in the process of schooling, working, and establishing relationships. Some patients have difficulties in communicating with people around them about diabetes.‘My previous research found that T1D patients are under great stress but generally don’t know how to relieve it, or to effectively communicate with families and friends to gain support.’[H3].‘Since I have been diagnosed with diabetes, I have not been in the mood for starting a romantic relationship. I strongly believe no one will accept a young man with diabetes as a boyfriend.’[P4].‘All my classmates know that I’m diabetic. Every time I inject insulin before a meal, I think they are pitying me. So I just hide. I don’t like discussing it with others.’[P11].Insulin is essential for blood glucose control in T1D. Both the dose and timing of bolus injections are key factors in controlling post-prandial glucose . However‘I want to learn the effect (PK-PD) of different insulin, like the time of onset, peak time, and etc.’[P6].‘Patients need to know the basics of insulin, such as its physiological effects and classification. This is the prerequisite of administering correct insulin at correct time.’[H7].‘Blood glucose levels may vary every day. Instead of fixed doses prescribed by the doctors, it’s more important for the patients to learn how to adjust insulin doses properly according to their own meals and activities.’[H10].HCPs also emphasize on self-adjustment of insulin doses in daily routine in order to help patients to maintain ‘a normal life’.Carbohydrates are the staple food in Chinese cuisine. Although cooking methods and ingredients are more diversified and harder to predict compared to western food culture, consensus was still reached that, along with insulin, identifying carbohydrates, knowing carb counting and carb-insulin ratio, are fundamental.‘Through understanding how carbohydrates and other ingredients affect blood glucose levels, patients can learn to inject boluses before meals or snacks. If they want to live a less restricted life while keeping stable blood glucose levels, carb counting is a basic skill.’[H9].‘I heard from other patients about reading food labels, but I still have no idea what to look at. Energy? Carbohydrates? What’s the meaning of reading these numbers anyway? I am so afraid of being in the supermarket now, dare not to buy anything.’[P9].Hypoglycaemic events occur to every T1D patients, but not everyone knows the right procedure to handle it. All basic dimensions of hypoglycaemia need to be elucidated.‘In fact, quite a few patients don’t realize that they are correcting hypoglycaemia in a wrong way. They need to learn how to treat and prevent hypoglycaemia correctly.’[H3].‘Besides, we need to let them understand what causes low blood glucose levels.’[H9].‘I want to know how to reduce hypoglycaemic events.’[P2].When it comes to the patients’ physical activity, the biggest obstacle is knowing the trend of glucose fluctuations during and after exercises. Some experienced repeated hypoglycaemia after household chores. Some didn’t know their glucose changes because they never checked before or after.‘I don’t know what type of exercise fits me. I assume exercise can lower blood sugar, but my sugar level can’t even drop for 1 mmol/L after running for 5 kilometres.’[P1].‘Physical activity definitely has profound effects on glucose levels thus should be discussed. For example, patients need to learn how glucose levels might fluctuate with different types, duration, and strength of activities; how to make certain adjustments on food intake and insulin dose before, during, and after physical activities.’[H1].‘I know the benefits of regular exercises, but it’s really easier said than done. I am so exhausted to even move my legs after work every day. I do want to know whether there is a better way to set myself in motion.’[P7].Patients also mentioned the lack of time, and more importantly, perseverance to exercise regularly.Screening for complications is recommended by diabetes guidelines , 6. A co‘There must be a session for (chronic) complications, especially for the screening part.’[H4].‘…How to prevent and detect early signs of diabetic complications.’[H5].‘If we could know what diabetic complications feel like, probably we would pay more attention to them.’[P4].Participants considered an opportunity for further discussion with HCPs and experienced patients a good summary of the whole course.‘There need to be a part where patients can freely and directly ask whatever questions they have during the course.’[H1].‘Question & Answer must be included… To guarantee that each attendee can have at least one actual problem solved.’[P5].SEPs in other countries are mainly conducted by a team of one diabetes education nurse and one dietician. Nevertheless, most HCPs interviewed embraced a multidisciplinary team of educators, with psychologists and physical therapists included.‘A multidisciplinary team is essential. Different contents should be elucidated by specific specialists—diets by dieticians, dose adjustment by diabetologists, and so on.’[H4].‘Experiences from well-managed patients will be quite valuable. ‘Long illness makes the patient a good doctor’. We cannot learn those personal experiences from textbooks or professionals. Plus, they can inspire us to never lose hope.’[P12].From patients’ perspectives, peer support was indispensable. Patients are more likely to gain strength from people in the same condition.Face-to-face group learning remains the most effective setting by all participants. However, different from the large learning groups commonly seen among T2D patients in China, ‘small-group education’ was preferred for T1D. Meanwhile, with the rapid development of mobile health  technologies, diabetes remote learning apps has become a welcomed supplement.‘I prefer patients sitting together because we can learn from each other. However, I’m not good at memorizing things, so it would be very helpful if we can watch video recordings back home.’[P4].‘Small-group teaching followed by remote learning is better. Remote learning should be via video recordings. It is more direct and intuitive.’[H8].Most interviewees agreed that the length of face-to-face education should not exceed three days.‘Weekends are good options. It won’t conflict with any work. Besides, I think it will be too much to digest if the course lasts for more than 3 full days.’[P8].‘A quiz held right after class is the most straight forward way to test the acceptance and outcome of teaching. You could know from attendees’ responses how well they have learned during class, and what needs to be explained again.’[H2].‘An extremely important indicator is patients’ responses, such as their experiences, degree of satisfaction, and so forth.’[H10].‘I think the final evaluation needs to be thorough, including both biomedical and psychological outcomes.’.Questions about quality assurance were only administered to HCPs. Three themes were considered useful for developing an assessment system: ‘After-class quiz’, ‘Patient’s feedback’, and ‘Long-term evaluation of effectiveness’. While the first two themes mainly aim at examining immediate knowledge capture, general acceptance by patients and comprehensibility of the programme, the third theme evaluates effectiveness to provide insights for further refinement of the programme.All 17 themes reached consensus and results are shown in Table In total, 20 T1D patients  framework, ‘a cyclic process that evolves over time and continuous throughout the instructional planning and implementation process’ . ADDIE iSemi-structured interview is a commonly used approach for data collection in qualitative researches . DiverseThe validity of results from interviews was further verified with Delphi method. Delphi consultation is a validated and widely used technique for obtaining a consensus , 24. In Derived from DTTP in Dusseldorf, Germany , 27, strAnother aspect that gives rise to regional divergence is the intensity of course delivery. Most SEPs in the UK are either 5 consecutive days or over several weeks , 30. PRIRegardless of course intensity, some education sessions, such as calculating insulin doses, are generally considered challenging by both educators and course participants . Many paWe developed TELSA—the first SEP targeted at Chinese adult T1D patients, using semi-structured interviews and Delphi method. The course was piloted and shown to be applicable in the local medical, social, and cultural environment. We will further conduct randomized controlled trials to evaluate the effectiveness of the programme. Strategies aiming at post-course follow-up supports will also be integrated to enhance learning.Additional file 1: Table S1 Interview guideline for adult patients with T1D. Table S2 Interview guideline for HCPs.Additional file 2: Table S3 Characteristics of participants in Delphi consultation.Additional file 3: Quiz and a sample of feedback questionnaire.Additional file 4: Table S4 Characteristics of T1D patients in preliminary courses.Additional file 5: Table S5 Class schedule of TELSA.


This review addresses the design and materials important to the development of tandem dye-sensitized photoelectrochemical cells for solar H2 production and highlights current published reports detailing systems capable of spontaneous H2 formation from water using only dye-sensitized interfaces for light capture.If generated from water using renewable energy, hydrogen could serve as a carbon-zero, environmentally benign fuel to meet the needs of modern society. Photoelectrochemical cells integrate the absorption and conversion of solar energy and chemical catalysis for the generation of high value products. Tandem photoelectrochemical devices have demonstrated impressive solar-to-hydrogen conversion efficiencies but have not become economically relevant due to high production cost. Dye-sensitized solar cells, those based on a monolayer of molecular dye adsorbed to a high surface area, optically transparent semiconductor electrode, offer a possible route to realizing tandem photochemical systems for H While coal, petroleum, and natural gas make ideal fuel stuffs—energy dense, stable, readily transportable—the scientific community has long warned that the re-introduction of sequestered carbon to the active geologic cycle will have profound and detrimental effects on the Earth-climate system , might m2 production comes from natural gas reformation. This unfortunately creates a carbon footprint for what should be a carbon free fuel cycle. Hydrogen formed from water electrolysis would create no carbon emissions assuming that the electricity to drive the electrolysis comes from renewable generation—e.g., wind, hydroelectric, geothermal, or solar. This approach is not technology limited and with the development of favorable market conditions and/or implementation of environmentally conscious public policies, could become a viable path to supplying H2 fuel. Regardless of how the energy is sourced, the decomposition of water to H2 and O2 products  for H2 production does just this and offers, at a system level, the means to achieve the highest possible efficiency for using solar energy to form H2 from water.To realize the potential environmental benefits of hydrogen fuel requires its renewable generation and currently industrial Hucts Eq.  is both 2 production from water splitting, reporting 12.4% light-to-hydrogen efficiency (~ 11 sun illumination intensity) using main group III-V semiconductor light absorbers 2+, 1) can be covalently anchored on oxide semiconductor surfaces    catalysts first reported by Sun and coworkers [2] (isoq = isoquinoline) showed a water oxidation turnover frequency of > 300 s−1 which compares to that of the oxygen-evolving complex of Photosystem II of between 100–400 s−1 [IV dimer reaction intermediate in which water coordinates to the [Ru(bda)(L)2] catalyst as the seventh ligand [2] molecular catalysts to TiO2 based dye-sensitized photoanodes enabled the first demonstration of > 1 mA cm−2 photocurrent densities observed in a DSPEC system  (dmgBF2 = difluoroboryldimethylglyoximato) complex though in this case modified with phosphonate anchoring groups  type water oxidation catalysts. In this system, light first passed through the DSPEC photoanode where 6 2)]2+) absorbs wavelengths shorter than 490 nm before passing on to the DSSC photoanode where the 17 absorbs out to 580 nm. While not the optimal threshold wavelengths for solar water splitting, this system achieved a steady state photocurrent density of ~ 40 μA cm−2 leading to an observed STH efficiency of 0.06%. This study marked the first instance where only n-type dye-sensitized photoanodes were used to carryout unassisted solar water splitting.Meyer and co-workers reported a tandem DSPEC-DSSC system that did achieve overall water splitting to Hom light . Two criterfaces  and the . recently reported an improved system which achieved a remarkable STH efficiency of 1.5% [2 (1) sensitized SnO2@TiO2 core–shell photoanode with co-adsorbed [Ru(bda)2] WOC. A Pt dark cathode completed the DSPEC component of the tandem cell, and under 1 sun illumination the system achieved a photocurrent density of ~ 1 mA cm−2 over a 1 h photolysis period. This improved performance was largely due to the enhanced performance of the DSPEC component as compared to the earlier reported DSPEC-DSSC, though the more-red absorption and modestly higher open circuit voltage of the OSC contributed to the higher observed STH. The remarkable improvement in solar to hydrogen efficiency, representing an order of magnitude increase compared to the previous systems, over such a short time from the first reports of tandem dye-sensitized water splitting systems show the promise of this type of tandem photocell. With continued progress this approach should offer a viable alternative to the semiconductor absorber-based systems.Carrying on progress with tandem DSPEC based water splitting, Wang et al of 1.5% . In this of 1.5%  donor an of 1.5%  acceptor. details the use of a monolithic tandem junction comprised of a p/n-Si PV embedded base layer with outer mesoporous TiO2 surface with adsorbed 1 and [Ru(bda)(4-O-(CH2)3-PO3H2-pyr)2] (pyr = pyridine) dye/catalyst monolayer [−2 current density over a 15 min illumination period at 1 sun intensity. Microsensor detection of H2 and collector-generator analysis for O2 demonstrated the production of each at Faradaic efficiencies of 100 and 79% respectively. Though unreported, the STH efficiency is estimated at 0.1%. Pursuing monolithic tandem DSPEC such as this provides another avenue toward leveraging the adaptable and tunable nature of dye-sensitized surfaces for unbiased solar water splitting.One other tandem systems incorporating a DSPEC photoanode merits mention though it does not fit in exactly the same vein as the systems described above. The report by Sheridan et alonolayer . The p/nTandem photochemical cells offer the best opportunity for realizing conversion efficiencies that could ultimately provide a sustainable and alternate means of supplying chemical fuel to society in place of fossilized carbon sources. While the current state-of-the-art dye-sensitized tandem photochemical cells lag in terms of STH efficiency compared to those using semiconductor light absorbing materials, the inherent flexibility in modifying and tailoring a dye-sensitized interface to achieve specific absorption and redox properties could provide the means to push realizable efficiencies further toward the theoretical ceiling. While substantial challenges remain including the need to improve long-term stability, finding ever more active and robust catalysts for the required half reactions of water splitting—especially that of water oxidation—and constructing and controlling interfacial architectures to avoid non-productive charge recombination, tandem DSPEC systems have improved STH efficiencies by a factor of 10 across only a few studies in as many years. With continued progress these systems could offer low-cost and easily fabricated devices for efficient solar fuel production and could have other potential applications such as has been shown recently for the depolymerization of lignin .


Scleractinian “stony” corals are major habitat engineers, whose skeletons form the framework for the highly diverse, yet increasingly threatened, coral reef ecosystem. Fossil coral skeletons also present a rich record that enables paleontological analysis of coral origins, tracing them back to the Triassic (~241 Myr). While numerous invertebrate lineages were eradicated at the last major mass extinction boundary, the Cretaceous-Tertiary/K-T (66 Myr), a number of Scleractinian corals survived. We review this history and assess traits correlated with K-T mass extinction survival. Disaster-related “survival” traits that emerged from our analysis are: (1) deep water residing (>100 m); (2) cosmopolitan distributions, (3) non-symbiotic, (4) solitary or small colonies and (5) bleaching-resistant. We then compared these traits to the traits of modern Scleractinian corals, using to IUCN Red List data, and report that corals with these same survival traits have relatively stable populations, while those lacking them are presently decreasing in abundance and diversity. This shows corals exhibiting a similar dynamic survival response as seen at the last major extinction, the K-T. While these results could be seen as promising, that some corals may survive the Anthropocene extinction, they also highlight how our relatively-fragile Primate order does not possess analogous “survival” characteristics, nor have a record of mass extinction survival as some corals are capable. For these reasons they have been extensively studied and relatively well-monitored over the past few decades3. The International Union for Conservation of Nature (IUCN) Red List has recently reported an alarming trend, ca. 30% of the 96,500 species assessed on the IUCN Red List being threatened with extinction4, including one third of the world’s corals5.Scleractinian corals represent an ideal taxon to serve as a model for describing past and predicting future environmental trajectories of mass extinctions. Coral skeletons are widespread and well-preserved in the fossil record, and as reef-builders, Scleractinians support and promote biodiversity hotspots. While coral reefs represent only 0.2% of the oceans’ area, they harbor ~95,000 described species and represent about 5% of the world’s known species and ~35% of known marine species6 with increasing number of studies confirming that current extinction rates are more than 100 times higher than background extinction rates7. This rate of species loss is on par with previous extinction events10. This study tests the hypothesis of common evolutionary traits/dynamics that characterize both K-T and the current Anthropocene survivors. We use Scleractinian corals as the test subject due to their secretion of a calcium carbonate skeleton that provides a rich history for paleontological analysis that extends back to the Triassic period12.The earth has experienced five major mass extinction events (“The Big Five”) since the Cambrian period, each resulting in the loss of more than three-quarters of species biodiversity over a geologically short time interval. These events occurred at the 1) Late Ordovician (440 Mya), 2) Late Devonian (370–350 Mya), 3) End-Permian (251 Mya), 4) End-Triassic (201 Mya) and 5) End-Cretaceous, which is referred to as the ‘K-T’ event (66 Mya). It has been proposed that the sixth mass extinction is currently in progress13. It is widely accepted that this extinction was triggered by a giant (10 km in diameter) meteorite impact at Chicxulub, Yucatan Peninsula, Mexico 66 million years ago14. The bolide event likely caused earthquakes, tsunamis and intense heat pulse that led to global wildfires, which had a strong impact on non-marine organisms15. The initial “fireball stage” was followed by a global “impact winter” caused by dust particles and other aerosols blocking sunlight, resulting in a 6 °C cooling of sea surface temperature. The impact winter lasted months to decades and influenced both marine and terrestrial productivity, leading to nutrient soup accumulations, and the formation of stable cold deep water16. In addition, sulfur and nitrogen volatile compounds were injected to the atmosphere, possibly leading to acid rain and ocean acidification17. The acid rain increased chemical weathering rates and resulted in a higher flux of bioavailable phosphorus into the ocean, resulting in additional nutrients to the nutrient soup18. The K-T boundary catastrophe reached deep-water dwellers, inferred by significant deterioration of deep-water benthic foraminifera communities19. After the relatively short-lived cool impact winter, rapid warming brought sea surface temperature (SST) back to pre-K-T levels followed by long-term warming, apparently related to greenhouse gases release20. Some other scenarios for the K-T event drivers include volcanism, multiple asteroid impacts, climatic changes and biotic stresses already affecting organisms previous to the K-T, as well as combinations of these factors9. Recent modeling experiments predict that the “impact winter” might have been balanced, or even outweighed, by global warming derived by water vapors, leading to a greenhouse effect21. Scleractinian corals are expected to be particularly sensitive to bespoke environmental changes such as: (1) prolonged darkness, (2) major temperature changes, (3) eutrophication and (4) ocean acidification.The K–T mass extinction was one of the most destructive events in the Phanerozoic, resulting in global extinction of ~40% of total genera and 47% of marine invertebrate genera22. Coral reefs were re-established ~2–5 Ma after the K-T, and became increasingly abundant in the Eocene (~10 Ma later). These reefs were composed of mostly novel community types, compared to previous Cretaceous reefs22.The recovery of coral reefs following the K-T event began with coralline algae, sometimes accompanied by photosymbiotic benthic foraminifera. While reef-building photosymbiotic corals suffered great losses at the End-Cretaceous, some genera survived and later became important reef builders in the CenozoicHomo sapiens first appear in the fossil record ~315,000 years ago23 and since that time there have been several regional extinctions, becoming more frequent following the agricultural/neolithic revolution beginning ~10,000 years ago9. However, since the Industrial Revolution (1760–1840) and particularly after 1950, the Earth’s biosphere has experienced rapid changes in atmospheric conditions, warming of global temperatures and rising CO2 levels. These are the highest levels over the past 800,000 years and temperatures are predicted to increase by ~1.8–3.4 °C and CO2 levels by 170–420 ppm over the next century25. Increased atmospheric CO2 concentrations are causing measurable ocean acidification26. This together with habitat fragmentation, pollution, overfishing and overhunting, the introduction of invasive species and pathogens, and expanding human biomass represents a combination of global wide extreme stressors combining in unprecedented ways for most species27. If these stressors are not mitigated, 75% of species are predicted to face extinction within the next few centuries to millennia6. Stony corals are particularly sensitive and are heavily impacted by direct human interferences , as well as warming and ocean acidification. They are predicted to suffer more than 30–50% extinction in the coming decades and century, respectively24.28 with species assigned categories, from “extinct” to “of least concern”. This assignment is performed by taxonomic experts according to the IUCN Red List categories and criteria29 that consider reports of population reduction, as well as threats and risk factors such as bleaching/disease susceptibility, severe fragmentation and destruction of habitat. In this study, we used data from the coral fossil record and the current IUCN Red List classification to compare coral survival between the K-T and the current extinction events.Realizing that extinction risk is realistic to increasing number of species in our era, the International Union for Conservation of Nature (IUCN) initiated the Red List of Threatened Species in 1964. It aimed to classify organisms at extinction risk in categories that may assist in managing conservation efforts efficiently. The Red List is recognized as the most comprehensive assessment of organisms’ extinction riskhttp://paleobiodb.org). These data were joined with various extant coral traits including the IUCN Red List classification from the Coral Trait Database . Data were grouped at the genus level in order to allow robust comparison with the fossil record and overcoming some uncertainties related to species level recognition.Fossil occurrence data for Anthozoans  were collected from the Paleobiology Database . Results were further analyzed if the number of genera in a bin was >10. The analysis included binning of data into 5 M years bins and then calculating the percentage or average  of each trait in each time bin.30). Although adaptation of a coral’s population to environmental conditions is a known phenomenon and plasticity of bleaching susceptibility has been documented for some species31, a significant change in a genus bleaching susceptibility is uncommon32. “Winners and losers” taxa are indicated for bleaching episodes35 often related to consistent morphological features37. Hence, we assumed there would be differences in bleaching and disease susceptibility among genera even if some adaptation takes place.For this analysis, each fossil that has an extant representative at the genus level (even if the species is extinct) was assumed to be characterized with the same traits as its extant representative. Using this approach, we could infer relevant traits that were not evident in the fossil record (e.g. bleaching and disease susceptibility). Since only ~10% of extant Scleractinian genera are found earlier than the K-T boundary (22 of 223 genera in the database), the traits that were inferred from modern corals possessed smaller representation than those from fossils  should be analyzed with caution. One-way Analysis of Similarities (ANOSIM) was performed to statistically differentiate the characteristic binary traits of the grouping (“survivors” and “extinct”). This test is a-parametric and does not assume normality of the data. The calculated test statistic R has a value between −1 and 1 and rarely goes below 038. When R = 1, all the repeats within a group are similar to each other, rather than to repeats in other groups. When R = 0, the similarity within and among all groups is the same on average. All values are presented at a confidence interval of 95%. Similarity Percentage Analysis (SIMPER) identifies the “important” component from all the characteristic binary traits; i.e., the relative contribution of each trait to the dissimilarity between all inter-group pairs of samples. All multivariate analyses were performed with R i386 3.3.3.The characteristic binary traits of 102 coral genera, for which the full suite of metadata was available (Table 40) and a 12% decrease in the occupation of shallow habitats (depth <100 m) relative to pre K-T values. We also note a higher prevalence of slow growing genera (average growth rate <10 mm yr−1) around the K-T event (89% at the late Cretaceous as opposed to 60% at the Pliocene-Pleistocene), manifested also as slow average growth rate (~7 mm yr−1) at 60–66 Mya  “Extinct”; 2) “Extinct in the Wild”; 3) “Critically Endangered”; 4) “Endangered”; 5) “Vulnerable”, 6) “Near Threatened” and 7) “Least Concern”. Our analyses showed that some traits were less represented in categories 1–5 (Extinct-Vulnerable) than in 6–7 (Near Threatened-Least Concern) categories  (averaging 62 mm yr−1 in Threatened Red List categories vs. 24 mm yr−1 in “Least Concern” and “Near Threatened”); and are capable of occupying deep reefs (>100 m depth) (1.8% in “Least Concern” and “Near Threatened” vs. 0.2% in the Threatened Red List categories). Of the corals reported to be sensitive or resistant to disease, all of the “Critically Endangered” were disease-susceptible. Bleaching resistance was found to be in the highest proportion (31%) within the “Least Concern” category, but among the “Threatened” categories it was higher in the “Critically endangered” than in “Vulnerable” categories (25% and 9% respectively).We find that corals less endangered by the current extinction are solitary ; do not contain zooxanthellae (1.5% in “Least Concern” and “Near Threatened” vs. 0.2% in the Threatened Red List categories); and build only small colonies (<200 mm) (averaged 269 cm in Threatened Red List categories vs. 161 cm in “Least Concern” and “Near Threatened”). The less endangered corals have larger corallites (>3 mm) (averaging 3.3 cm in Threatened Red List categories vs. 6.0 cm in “Least Concern” and “Near Threatened”), are slow-growers (<50 mm yrp < 0.01)  was highest through the K-T event Fig. , implyin01) Fig. . SIMPER 01) Fig. . Further44. Understanding the effects of biological traits on coral survival and future community structure is a matter of high priority45, both for what it predicts for the future of coral reefs and as a general model for the selective survival of various biological communities. In this study we searched the existing body of coral fossil data and coral traits through the K-T boundary event, together with their contemporary extinction status, to determine whether there are “survival traits” that are common both among survivors of the last major mass extinction (K-T). and at the present Anthropocene mass extinction.Deducing future trajectories, based upon past extinction events, has received increased scientific attention over the past decade47. However, this result should be taken with caution regarding the Anthropocene extinction as it is based on analyzes of the IUCN Red List categories whose assessment might also take geographical distributions parameters into account.We found wide geographical distribution to be the most important determinant of coral survival both through the K-T and the Anthropocene Table , Fig. 2.40. We also show that these genera evolved in higher proportions following the extinction 39 to K-T and Anthropocene extinctions may be explained by the combined effect of eutrophication, warming and acidification which characterize both the modern situation and some parts of the K-T event50. These environmental changes in the modern ocean impact mostly euphotic surface waters and are particularly threatening to colonial symbiotic genera that reside in the upper, photic ocean, where they outcompete their algae competitors in low-nutrients environments. An alternative hypothesis is that Scleractinian corals retreated into deeper, off-reef niches where light was scarce40. In the deep reef environment, non-photosymbiotic solitary coral genera have an advantage, while symbiotic corals suffered higher extinction rates on shallow reef habitats during the K-T40. Decreasing average growth rates through the K-T event may also be related to the drop of photosymbiosis which would diminish growth rates due to lesser energy and photosynthates supply51. Decreasing growth rates may also reflect the coinciding high bleaching resistance found during the K-T .Our analysis shows that colonial, symbiotic, shallow Scleractinian genera were particularly impacted by the K-T extinction, a finding that is in agreement withion Fig.  and are ion Fig.  and comm54 that shows higher disease effects coinciding with past thermal stress history. The high proportion of bleaching resistant genera after the K-T event reinforces the suggestion that bleaching resistance is a significant survival factor during mass extinctions55. This finding offers another perspective to the “adaptive bleaching hypothesis”56, which states that when environmental conditions change, one or more clades of photosymbionts is replaced by a new symbiotic consortium of photosymbionts that are better suited to the current conditions. Interestingly, for the Anthropocene event, bleaching susceptibility was found to be in the highest proportion (91%) within “Vulnerable”, rather than in the “Critical” (75%) Red List category. This could be interpreted as the bleaching threat being not yet fully established, or that other factors are stronger in determining probable extinction patterns. A recent model for coral endurance through global warming predicts that bleaching resistance will become a dominant factor for future coral survival41.In addition, coral genera with relatively greater disease or thermal stress resistance, were relatively dominant  in those that survived the K-T event and Paleocene and Eocene high temperatures Fig. . Decreas57 and large colonial corals survived. A similar trend, of higher extinction risk for smaller organisms during “background extinctions” as opposed to higher extinction risk for large bodied creatures in the Anthropocene, was found for marine vertebrates and mollusks58. These discrepancies imply different mechanisms allowing a coral to survive during moderate versus mass extinction. In moderate extinction conditions, large colony size  allows a coral to survive some disturbances. While in mass extinction conditions, such as the K-T (this study), small colony size allows corals in “sheltered” niches to survive. This tendency of smaller coral genera to survive through a mass extinction resembles the well-known “Lilliput Effect”, a trend towards smaller size of faunal elements associated with mass extinction events59. In this sense, the fate of large corals is similar to that of large terrestrial vertebrates, who were drastically impacted by the K-T mass extinction event60.There is potentially a difference in corals surviving moderate extinction (by possessing large colony size) and mass extinctions . Ecological characteristics were previously found to be an important determinant of extinction risk in Caribbean reef-corals in the Neogene with colony size as the most important trait determining extinction rate. It was found that for the Neogene moderate extinctions, corals with small, massive colonies were most vulnerablehttps://www.iucnredlist.org) categories , as judged by the Paleocene re-establishment of algal symbiosis39. While the slow recovery time of coral reefs following a mass extinction is distressing, we also call attention that Primates  are also increasingly becoming threatened with extinction61. And unlike the Order Scleractinia, Primates do not possess analogous “survival” traits that enable some species to transcend major extinction boundaries, nor does Homo sapiens or any other Primate species, have a track record of mass extinction survival.We suggest that the similarity in traits allowing coral survival exists through two very different extinction events Table  imply th


Based on these results, we deduce that common hydrophobic materials possess surface-bound negative charge. Thus, when these surfaces are submerged in water, hydrated cations form an electrical double layer. Furthermore, we demonstrate that the primary role of hydrophobicity is to facilitate water-substrate separation without leaving a significant amount of liquid behind. These results advance the fundamental understanding of water-hydrophobe interfaces and should translate into superior materials and technologies for energy transduction, electrowetting, and separation processes, among others.The mechanisms leading to the electrification of water when it comes in contact with hydrophobic surfaces remains a research frontier in chemical science. A clear understanding of these mechanisms could, for instance, aid the rational design of triboelectric generators and micro- and nano-fluidic devices. Here, we investigate the origins of the excess positive charges incurred on water droplets that are dispensed from capillaries made of polypropylene, perfluorodecyltrichlorosilane-coated glass, and polytetrafluoroethylene. Results demonstrate that the magnitude and sign of electrical charges vary depending on: the hydrophobicity/hydrophilicity of the capillary; the presence/absence of a water reservoir inside the capillary; the chemical and physical properties of aqueous solutions such as pH, ionic strength, dielectric constant and dissolved CO Electrification of water upon contact with hydrophobic surfaces is a ubiquitous but poorly understood phenomenon. Here, the authors pinpoint the factors responsible for the excess positive charge carried by water droplets dispensed from hydrophobic capillaries, thereby answering some outstanding questions and raising new ones. The electrification of water against hydrophobic surfaces (hereafter referred to as water-hydrophobe interfaces) plays an important role in various applied and natural contexts, such as pipetting9, triboelectric power generation12, hydrogen generation14, mitigating dust deposition on solar panels15, preventing fire hazards in granular flows16, and precipitation and thundercloud charging18. However, the causes and mechanisms underlying this electrification process are still intensely debated37.Water becomes electrified when it comes in contact with hydrophobic media. Electrification underlies various curious phenomena, such as the electrostatic manipulation of droplets placed on hydrophobic surfaces48 and hydronium ions55, the dipolar organization of interfacial water56, the partial charge transfer between the O and H atoms of interfacial water58 or between interfacial water and oil molecules59, the adsorption of bicarbonate ions due to the dissolution of ambient CO260, contamination66, reactive chemical groups69, electrons trapped on the surface of insulators72 and mechanoradicals74. With the exception of surface-bound electrons, these mechanisms assume that common hydrophobic surfaces such as polypropylene and perfluorocarbons are electrically neutral in air. In this work, we designed elemental laboratory experiments to answer the following interrelated questions:i.Why do water-hydrophobe interfaces become electrically charged?ii.How do the properties of aqueous solutions, solid surfaces and the environment impact the electrification of water at water-hydrophobe interfaces?iii.Could other liquids besides water become electrified when brought into contact with hydrophobic surfaces? What is the role of hydrophobicity in the context of electrification at water-hydrophobe interfaces?A variety of mechanisms have been put forth to explain electrification of water in contact with solid/liquid/gaseous hydrophobes, including the specific adsorption of hydroxide ions75.Based on this experimental investigation, we deduce that the surfaces of common hydrophobes, such as polypropylene, FDTS, and PTFE, are negatively charged. Thus, when these surfaces come into contact with a liquid containing solvated ions, such as water, cations form an electrical double layer at the interface in accordance to the electrical double layer theoryθrθA) and receding (θR) contact angles using sessile deionized water droplets of volume −1, and found them to be θA = 105° ± 1° and θR = 72° ± 1° respectively (Methods). The polypropylene surfaces of the pipette tips exhibited θA = 113° ± 2° and θR = 62° ± 2°. Hereafter, deionized water is referred to as water. Supplementary Fig. We quantitatively investigated the electrification of deionized water droplets dispensed from polypropylene pipette tips and borosilicate glass capillaries (see Methods). Glass capillaries allowed us to precisely control the solid-liquid interfacial tension. For instance, freshly cleaned glass capillaries were superhydrophilic, characterized by ultralow apparent contact angles, mentclass2pt{minim2 aluminum plates that ensured a uniform electric field in the central region of <4 × 4 × 4 mm3 occupied by the droplets  and surface area, formed at the tip of hydrophobic and hydrophilic capillaries. We recorded the formed droplets’ behavior inside a parallel plate capacitor, which comprised of two 100 × 100 mm0 μL and ets Fig. ; and  equipped with a Faraday cup made of aluminum sheet to shield external interferences76 Fig. , Methodsq) carried by the droplets through their deflections under uniform electric fields. The balance of the electrostatic (FE) and gravitational forces (FG) acting on the pendant droplets gave rise to tilting angles, α,  as:m is the mass of the drop, g is the acceleration due to gravity, L is the distance between the plates of the capacitor, and E is the uniform electric field inside the capacitor (E = V/L). Then, the excess charge carried by the droplets (q) is:2, is:We used high-speed imaging to quantify the excess charges  the next two droplets did not show any deflection, and all the subsequent droplets were repelled away from the positive plate. Clearly, the droplets became increasingly repelled by the positive plate as the capillary emptied Fig. .In contrast to the hydrophobic capillaries, when hydrophilic glass capillaries were air-filled, the pendant water droplets were attracted to the positive plate, albeit only very mildly, and their estimated charge density did not scale with the electric field Fig. . However−1 regardless of the hydrophobicity/hydrophilicity of the capillary. While higher electric fields may eventually induce deflection20, but such studies are beyond the scope of this work as we are focused on aqueous interfaces specifically.We repeated these experiments using methanol and hexadecane Fig. . The penFaraday cup measurements Fig.  demonstr−1, through capillaries of varied surface chemistries77. To investigate the effects of dewetting speed relevant to our experiments, we withdrew 200 µL of water from an electroneutral water reservoir using polytetrafluoroethylene (PTFE) tubes of inner diameters 0.5 mm and 1 mm and then dispensed it at rates ranging from 0.06–2.4 mL min−1 (speeds: 0.1–20.4 cm s−1) inside the electrometer  if the hydrophobic capillaries selectively drew water with excess charge during the intake process. To test these hypotheses, we placed a water reservoir inside a Faraday cage and monitored changes in its electrical charge during water withdrawal/addition. Specifically, we placed 1 mL of water (reservoir) inside the Faraday cage and we extracted aliquots (15–50 μL) using capillaries of varying wettability, while logging the charge of the water reservoir , −2 (or 29 # μm−2), and −2 (or 7 # μm−2), respectively, where # refers to the number of electronic charges (Eq. To investigate the origins of water electrification we considered whether: (i) the excess charge originated at the interface of the water and the hydrophobic surface due to, for instance, the selective adsorption/desorption of Hoir Fig. . Simultaliquots 1–50 μL us2 concentration, and dielectric constant of different aqueous mixtures on the electrification process. In dilute electrolytes containing simple monovalent salts, the characteristic length-scale at which electrostatic interactions persist, is known as the Debye length  than those for NaCl, KBr, and NaOH cases  is confirmed by the complete recovery of electrification when the same tips were used to pipette deionized water  as a non-aqueous probe-liquid to investigate its electrification when brought into contact with polypropylene. We dissolved 1 mM NaCl in CH2I2; its surface tension, γ−182, facilitated the release of pendant droplets from the polypropylene capillaries at a flow rate ~3 mL min−1. The dispensed droplets  did not have excess charge  or FDTS-coated glass are negatively charged even in air. When water comes into contact with these surfaces, the ions present in the water, such as Hce Figs. , 6. Subsce Figs. b, 3. On ce Figs. .Fig. 6PrE, for the air-filled (or water-filled) scenarios  of linear scaling relationship between the excess charge density of the droplets, ios Fig.  follows Variational analysis of Equation  yields  and ionic strength are the key properties of aqueous solutions that govern the electrification. Dipole characteristics determine their ability to dissociate ion pairs, while ionic strength determines the electrostatic screening length. The negative charge density on hydrophobic surfaces is the other crucial factor for electrification – in fact, Lowell & co-workersing Fig. .2 atmosphere and found that electrification increased with increasing humidity, as has been noted before11 , and water in equilibrium with the atmosphere (pH ≈ 5.6), and found that the excess charges carried by the pendant water droplets decreased significantly as the water became more acidic due to the formation of carbonic acid similarly to the HCl solutions, as explained above  using a glove-box with 99% Nove Fig.  and 6B. 81, investigated the electrification at interfaces between insulators  as a function of rubbing speed, pressure, and duration. Under these conditions, mechanoradicals form and they undergo electron transfers and self-assemble into microscale mosaics comprising hydrocarbocations and fluorocarbanions (and with surface charge densities >25-times observed in our work). These mobile charges can be removed by dissolving them into common polar and apolar solvents. To test whether the surface-bound charge in our experiments can be removed by solvents, we utilized polypropylene pipettes and measured the charges of the dispensed water droplets before and after washing them with acetone and methanol 94 than ours. Further investigation is thus needed to systematically unravel the contributions of surface roughness, surface preparation and handling, and the ambient atmosphere in these experiments. The physical properties of liquids could also pose challenges in disentangling the factors underlying electrification. For instance, whereas mixing water with methanol reveals the dependence of interfacial charging on dielectric constants, it also lowers the surface tension, which makes the release of pendant droplets difficult; while diiodomethane’s surface tension facilitates satisfactory detachment of pendant droplets, its low dielectric constant precludes charge separation. The unavoidable hydrolysis and cross-linking of silanes, manual dispensing, variations in the ambient conditions, left-over nano/micro droplets inside pipettes, and the polarization of capillaries inside the capacitor could contribute to experimental errors.While we have tried to disentangle various aspects of electrification at water/hydrophobe interfaces, our experiments cannot address all the remaining questions in this field. For instance, the origin of the negative charge of these surfaces, as deduced from our experiments, remains unclear at this point and should be explored; we refer the reader to the reports by Lowell & co-workers92 containing electrical charges. These findings challenge the prevailing notions that the electrification of water-hydrophobe interfaces is driven exclusively by the dipolar arrangement of interfacial water, or the partial charge transfer between interfacial water and the hydrophobe, or due to the specific attachment/detachment of OH- or H3O+ ions at water-hydrophobe interfaces. We propose that any non-wetting liquid-solid interface, where the solid surface has a surface charge density and the liquid has dissolved ions and high dielectric constant, can cause droplet electrification. In principle, the electrification trends could reverse, e.g., from negative to positive, for a hydrophobic surface with positive charge. These findings advance the scientific understanding of electrification and rational design of technologies that involve electrowetting1, micro/nano fluidics and pipetting95, triboelectric power generation12, desalination97, and materials and surface engineering99, among others.Our experimental results demonstrate that when water comes into contact with common hydrophobic materials such as polypropylene, FDTS, and PTFE, cations partition to the solid-liquid interface. Thus, these surfaces have a negative surface charge density. The electrical double layer theory predicts ensuing trends: liquids with lower dielectric constants and higher ionic strengths experience lower electrification. The role of hydrophobicity on droplet charging is limited to the fact that when water leaves the surface, it does so without leaving a liquid film behind100.We prepared electrolyte stock solutions of 1 M NaOH, HCl, and NaCl that we diluted to adjust ionic strengths. To saturate deionized water with CO2, we bubbled the gas in it for 2 h, leading to pH ≈ 4 solutions.We used MilliQ Advantage 10  deionized water for this study. The water purification unit consisted of a Q-Gard pretreatment pack, UV lamp, Quantum cartridge (activated carbon and ion exchange resins) and a Q-Pod dispenser for final polishing2SO4: H2O2 = 4:1) for 10 min, followed by O2 plasma activation  for 10 min, and then the capillaries were placed in molecular vapor deposition system for coating using a 2-injection deposition cycle.  We determined the topography of the samples by Veeco Dimension Icon SPM  polypropylene pipettes , (2) PTFE tubes , and (3) cylindrical borosilicate glass capillaries  grafted with perfluorodecyltrichlorosilane (FDTS). The procedure of FDTS deposition was as following: we cleaned the capillaries with a fresh piranha solution (H polypropθA) and receding (θR) contact angles of sessile deionized water droplets of volume −1 . We found θA = 113° ± 2° and θR = 62° ± 1° on polypropylene, and θA = 105° ± 1° and θR = 72° ± 2° on FDTS-coated glass. The contact angles of water on oxygen-plasma treated glass capillaries were θA ≈ θR ≈ 5°.We characterized the water-repellence of the capillaries by measuring advancing .2 aluminum plates) connected to a Keithley’s 2290-10 high voltage source (range 0–10 kV). A Braintree Scientific BS-8000 syringe pump was employed to fill the capillaries with desired solutions and to form droplets at their tip. We recorded the deflections of the water droplets using a Phantom v1212 high-speed camera from Vision Research .For the direct measurement of the charge, we employed a Keithley 6517B Electrometer  connected to a homemade aluminum Faraday cup, which prevents the influence of external electrical sources on electrification. As a charged object reaches the cup, a charge of opposite polarity is induced on the inner electrode while the outer electrode is grounded, and the cup therefore acts as a capacitor. Due to a special low-current amplifier, the electrometer can detect very low charges by integrating the input current because the integrating capacitor is a part of the feedback loop Fig. 76. We reSupplementary InformationPeer Review FileDescription of Additional Supplementary FilesSupplementary Movie 1Supplementary Movie 2Supplementary Movie 3Supplementary Movie 4Supplementary Movie 5Supplementary Movie 6Supplementary Movie 7Supplementary Movie 8Supplementary Movie 9Supplementary Movie 10


Since these primordial times, the respiring mammalian cell has become entirely dependent on the constancy of electron flow with molecular O2 serving as the terminal electron acceptor in mitochondrial oxidative phosphorylation. Indeed, the ability to “sense” O2 and maintain homeostasis is considered one of the most important roles of the central nervous system (CNS) and likely represented a major driving force in the evolution of the human brain. Today, modern humans have evolved with an oversized brain committed to a continually active state and as a consequence, paradoxically vulnerable to failure if the O2 supply is interrupted. However, our pre-occupation with O2, the elixir of life, obscures the fact that it is a gas with a Janus Face, capable of sustaining life in physiologically controlled amounts yet paradoxically deadly to the CNS when in excess. A closer look at its quantum structure reveals precisely why; the triplet ground state diatomic O2 molecule is paramagnetic and exists in air as a free radical, constrained from reacting aggressively with the brain’s organic molecules due to its “spin restriction”, a thermodynamic quirk of evolutionary fate. By further exploring O2’s free radical “quantum quirkiness” including emergent quantum physiological phenomena, our understanding of precisely how the human brain senses O2 deprivation (hypoxia) and the elaborate redox-signaling defense mechanisms that defend O2 homeostasis has the potential to offer unique insights into the pathophysiology and treatment of human brain disease.Rising atmospheric oxygen (O This provided efficient, regulated metabolic support signaling the development of more complex structures such as the early brain in bilateri, conferring a clear evolutionary advantage over the 2 ATP/glucose yield by the more basic anerobic glycolytic reaction.Being surrounded by O2 and biological evolution is especially evident over the more recent Phanerozoic Eon (~ 550 Myr) when atmospheric levels increased to between 15 and 20% sparking the first animal body plans marking the advent of metazoan evolution  with a wing span in excess of 75 cm to flourish  a billion years before O2 became abundant in the atmosphere or ocean  or cohabitation with an oxidative photosynthesizing organism  and manganese (Mn) SOD isoforms among archaea and bacteria coupled with the independent evolution of the copper, zinc  isoform stands testament to this  with 25 billion tons of H2 (from H2O) to liberate 400 billion tons of O2 each year to maintain O2 at its current atmospheric level , more recent estimates suggest that the decline is more likely parabolic  with a neocortex that has come to constitute 80% of the brain with disproportionate increases observed in the prefrontal and posterior parietal cortex  increase in global cerebral blood flow to support rapid development in interneuron connectivity, synaptic activity and cognitive function  of ~ 25 mmHg and lack of O2-binding proteins, the brain’s O2 content is a meagre ~ 30 nmoL/mL such that given an average cerebral metabolic rate of oxygen (CMRO2) of 30 nmoL/mL/s, the O2 present would sustain metabolism for at best 1 s if blood supply were to be interrupted by anoxia  first described the existence of “dephlogisticated air” by heating mercuric oxide though this remains a hotly contested topic given that the gas had been purified and used to sustain human life and exercise by both a Polish alchemist  and Dutch engineer  some two centuries earlier. Priestley marvelled at its magical properties, capable of reigniting an ember of wood and increasing the survival of mice in a closed container although the luckless Carl Wilhelm Scheele (1742–1786) had produced the gas (“fire-air”) earlier and Antoine Laurent Lavoisier (1743–1794) provided a more informed description of the true nature of O2 naming it “oxigene” that had eluded Priestley who remained wedded to the “phlogiston theory” (West 2 lack (hypoxia), it is important to remind ourselves that our fundamental need for O2 obscures the fact that it is a toxic, mutagenic gas; deadly to the central nervous system (CNS) when in excess, yet paradoxically capable of sustaining life in physiologically controlled amounts.Despite it’s early appearance, the discovery of Ory” West . But bef2 molecule (3∑g−O2) exists in air as a free (di)radical  unpaired electron(s)] and not simply O2 since we’re choosing to ignore its most fascinating attribute! A lone electron is located in separate π*2p antibonding orbitals with the same spin quantum or spin states (+½ or ↑↑) consistent with Hund’s rule  , one of the electrons in the pair with a spin state opposite to that of the unpaired electron in O2 would “fit” comfortably into the orbital, to create a spin-opposed pair . However, this would not be the case with the other electron given its parallel spin state (↑↑), thus preventing it from “pairing up” in accordance with the Pauli Exclusion Principle. Thus, unlike most other oxidizing free radical species, this parallel spin renders O2 less reactive at “normal” concentrations despite its powerful oxidizing nature  is commonly used as part of the therapy of many circulatory disorders yet it is well known that the gas can exert toxic effects when not used judiciously, damaging the CNS, eyes and lungs.Paradoxically however, this gas and products of its metabolism becomes toxic at elevated PO2 toxicity were eventually linked to free radical formation   = + 940 mV], O2•- can be converted to hydrogen peroxide (H2O2) through reduction or dismutation and upon reaction with transition metal ions, ultimately forming the hydroxyl radical (OH•). This species is at the top of the free radical “league of reactivity” (EO΄ = + 2310 mV), thermodynamically capable of oxidizing any biomolecule that it collides with at a rate constant very near the diffusion limit  mitochondrion  may have evolved as an alternative form of endogenous antioxidant defense, limiting the concentration of (toxic) O2 to which the mitochondrion is exposed , given its inherent vulnerability to oxidative damage and corresponding respiratory dysfunction   and docosahexaenoic (C22:6) polyunsaturated fatty-acid side chains are especially susceptible to lipid peroxidation  to tissue metabolic demand such that cerebral homeostasis remains preserved consistent with the conservation of mass principle  and the crucian carp (Carassius carassius) who can effectively negotiate brain survival through specializations of brain physiology despite days to weeks of anoxia, entering into a state of deep hypometabolism and suppression of cellular injury during anoxia-reoxygenation  and peripheral  chemoreceptors that initiate cardiorespiratory reflexes that collectively serve to improve pulmonary gas exchange and cerebral O2 transport systems and rising atmospheric O2 levels (Taylor and McElwain α) subunit that heterodimerizes with the HIF-1beta (β) subunit to bind DNA. In normoxia, HIF-1α is oxidized (hydroxylated) by prolyl hydroxylases (PHDs) using α-ketoglutarate. The hydroxylated HIF-1α subunit interacts with the von Hippel–Lindau protein and is subsequently catabolized by proteasomes, such that HIF-1α is continuously synthesized and degraded. However, in hypoxia, HIF-1α hydroxylation does not occur, stabilizing HIF-1 where it binds to a hypoxia response element leading to the expression of a wide variety of genes involved in angiogenesis, cell proliferation, erythropoiesis, glucose transport, glycolytic metabolism and cell survival , whose complexity has increased in tandem with the evolution of ever-more sophisticated O Semenza .Fig. 4a 2 sensor  site with release to the intermembrane space and subsequent formation of hydrogen peroxide triggering HIF-α stabilization subsequent to PHD inactivation potentially related to phosphorylation or decreased bioavailability of Fe (II)  with evidence supporting a more direct link between molecular O2 and PHD inhibition/HIF activation , a genetically and metabolically diverse community containing the molecular origins of all present life forms estimated to have appeared ~ 3.8 Gya  allowing for reconstruction of the cellular processes that the protocell likely exploited /ROS-tolerant organism equipped with a primordial enzymatic antioxidant system that evolved prior to the photosynthetic rise in atmospheric O2  famous for his wave equation for non-relativistic quantum mechanics (QM) given by: ĤIψ > = EIψ >  was the first to ask if biological systems harness QM to perform a task more efficiently than even the best classical equivalent for selective advantage  as a simple straight line, “feeling out” the most efficient pathway to transport energy to the plant’s reaction center within a staggeringly short, 102 levels and evolution of life on Earth and the brain. The modern day human has evolved with an oversized brain exquisitely vulnerable to failure given that it is entirely reliant on O2, a toxic, mutagenic free radical gas that exists in air as a diradical, deadly in excess yet paradoxically capable of sustaining life in controlled physiological amounts. By further exploring O2’s “quantum quirkiness”, our understanding of precisely how the human brain senses hypoxia and the elaborate redox-signaling defense mechanisms that emerging evidence suggests may harness QM to preserve O2 homeostasis has the potential to offer unique insights into the pathophysiology and treatment of human brain disease.The current review has explored the intimate relationship between rising atmospheric O