Background: Evidence concerning the development of musculoskeletal health complaints (MHCs) among music students is limited due to inappropriate study designs. We aimed to assess the occurrences of MHCs and associated risk factors in freshmen music students compared to students from other disciplines. Methods: A prospective cohort study was conducted. Risk factors such as pain-related, physical, and psychosocial variables were measured at baseline. Episodes of MHCs were recorded monthly. Results: A total of 146 music students and 191 students from other disciplines were analyzed. In the cross-sectional comparison, pain-related, physical, and psychosocial variables were significantly altered in music students compared to students from other disciplines. Furthermore, music students with current MHCs differed significantly from music students without current MHCs with respect to physical health, pain, and history of MHCs. Our longitudinal analysis showed that monthly MHCs were higher in music students compared to students from other disciplines. Independent predictors for monthly MHCs in music students were current MHCs and reduced physical function. Predictors for MHCs in students from other disciplines were a history of MHCs and stress. Conclusions: We provided insight into the development of MHCs and risk factors in music students. This may help in the creation of targeted, evidence-based prevention and rehabilitation. Playing-related health complaints may impact practice, rehearsals, performances, and even the musical careers of music students; these complaints are a consequence of a complex interaction of physical, psychological, and psychosocial factors ,2,3,4. AHowever, there is only little knowledge of these issues due to aspects such as lack of prospective longitudinal study designs or low study quality ,16,21. MAs a consequence, we launched a prospective cohort study in 2015 at Osnabrück University of Applied Sciences to investigate musculoskeletal health complaints (MHCs) and associated risk factors in freshmen music students. More specifically, we aimed (1) to compare MHCs and MHC-related factors in music students to students from other disciplines at the start of their academic career ; (2) to report occurrences of MHCs within the first academic year; and (3) to identify risk factors and provide a prediction model for the occurrence of MHCs in music students using a prospective longitudinal analysis.Freshmen music students and freshmen from the same university but from different disciplines were eligible to participate in this prospective cohort study if they met the following criteria: (1) were a first-semester student at Osnabrück University of Applied Sciences; (2) agreed to participate; (3) were at least 18 years old; and (4) were able to communicate in German or English. Both freshmen music students and students from other disciplines were contacted through leaflets and visits to first-semester courses and seminars. Students from other disciplines were recruited from the Faculty of Business Management and Social Sciences. Participants were excluded from the study if the following criteria were relevant: (1) neurological, orthopedic, or psychiatric illness; (2) infectious or systemic diseases; and/or (3) the habitual use of analgesics or psychopharmaceuticals. The study was approved by Osnabrück University of Applied Sciences’ Ethics Review Board, and the article followed the STROBE guidelines . FurtherFor sample-size calculation, we aimed to identify a one-year incidence rate of 45% with a confidence band ranging from 40% to 50%. Therefore, we calculated a total sample size of 370 .Berque’s modification  of Zaza’Demographic data: we developed a questionnaire with the following characteristics: age, height, weight, BMI, weekly sports in hours (h), hours of sleep, tobacco use, alcohol consumption, and sex. In addition, music students were asked several questions about their practice habits .Core strength endurance: core strength endurance was measured by conducting front planks and the extensor endurance Biering-Sørensen (EEBS) test ,26. In bp-values of ANOVA: <0.001–0.06) [Hypermobility: general hypermobility was assessed using the Beighton score, ranging from 0 to 9 points, indicating very low to very high general hypermobility . This te01–0.06) .Cervical range of motion (CROM): the active range of joint motion of the cervical spine was more generally assessed using a cervical range-of-motion goniometer . The CROM device is considered valid (Pearson’s correlation: 0.93–0.98) , inter-r2/s. The value at which the sensation of “pressure” changed to one of “pain or discomfort” was recorded. Three measurements were taken for each muscle and averaged for analysis. PPT is a valid (Pearson’s correlation: 0.99) and intrareliable (ICC: 0.7–0.94) method used to measure mechanosensitivity [Mechanosensitivity: subjects’ mechanical pressure pain threshold (PPT) was assessed over predefined anatomical points for various muscles of the upper and lower extremities, the trunk, and the head, including musculus gastrocnemius lateralis, m. semi spinalis capitis, m. levator scapulae, m. trapezius pars transversus, the origin of wrist extensors, the origin of wrist flexors, m. sternocleidomastoideus, m. masseter, and m. temporalis. Measurements were performed using an algometer . The pressure was increased at a constant rate of approximately 1 kg/cmsitivity ,37.Health-related quality of life: the Short-Form Health Survey 12 (SF12) was used to measure health-related quality of life. Eight sub-scores addressed physical and mental health ,39,40. TStress and stress symptoms: the Stress and Coping Inventory (SCI) was used to evaluate stress and stress symptoms. For our purposes, only the dimension of stress symptoms was analyzed. We also used the Hospital Anxiety and Depression Scale (HADS). This questionnaire is valid (correlation coefficient: 0.67–0.77) and reliable  .Perfectionism: finally, we used the Frost Multidimensional Perfectionism Scale—German (FMPS-D) to evaluate subjects’ perfectionism. The FMPS-D is a valid (correlation coefficient: 0.57–0.85) and reliable  instrument .Performance anxiety: for the group of freshman music students, we conducted the Kenny Music Performance Anxiety Inventory (K-MPAI) test to assess performance anxiety. It is considered to be valid (correlation coefficient: 0.12–0.88) and intrareliable  ,44,45,46p-value of <0.05 was considered significant if not stated otherwise. We compared the study group’s baseline characteristics and demographic data using Chi-square tests and independent t-tests for categorical and continuous data, respectively. We also determined descriptive statistics such as means, standard deviations, and counts (percentages).The statistical analysis adhered to the analysis strategy described in the pilot study by Ballenberger et al. . All staFor the baseline analysis, we used univariate linear regression and logistic regression models. The effects are given as standardized mean differences (SMD) and odds ratios (OR), which made it possible to compare effects across different outcome measurements.p-value of <0.1 was considered significant in order to gain power and not miss true interaction effects [The goal of the univariate longitudinal analysis was to identify risk factors (predictors) for the emergence of monthly MHCs in music students and compare them to those in students from other disciplines. Here, we employed a general linear mixed model with binomial distribution to account for the correlated data structure (repeated measurements). The effects are given as odds ratios. In addition, we modeled the interaction between groups (music students and students from other disciplines) and the history of MHCs and health-related factors to evaluate whether risk factors for monthly MHCs differed significantly between groups. Here, a  effects . All unip-value was <0.1. The predictive accuracy of the model was determined by calculating the area under the ROC curve (AUCs).The goal of the multivariate longitudinal analysis was to identify a set of predictors/risk factors for monthly events of MHCs in music students. Based on the univariate longitudinal analysis, we entered potential candidate variables for the prediction model if their We employed residual diagnostics and plots to check the validity of all regression models.p < 0.05), respectively. Students from other disciplines were mainly freshmen from health sciences, business sciences, and social work, representing a cross-section of the faculty. Measurements were taken during the first three months of each cohort’s first semester. The first monthly online questionnaire was sent out directly after the completion of baseline measurements. Out of 337 subjects, 190 (97 music students and 93 students from other disciplines) completed at least one monthly questionnaire. This corresponds to a total response rate of 56% (66% in music students and 49% in students from other disciplines). A total of 1231 out of 2280 (190 × 12 months) maximally possible monthly completed questionnaires were completed. This corresponds to a completion rate of 54% in both cohorts. On average, music students completed 6.20 ± 4.08 monthly questionnaires, and students from other disciplines completed 6.20 ± 4.52 monthly questionnaires, respectively. In each cohort, 10% of the participants completed the monthly questionnaires fully (12 months).From 2015 to 2020, six cohorts totaling 337 subjects  and 191 students  from other disciplines) participated in the study. The mean age of the music students and students from other disciplines was 21.6 ± 3.17 and 22.88 ± 3.82 , higher pain (SF12), and, more often, current MHCs. Furthermore, mental health (SF12) was lower, while stress symptoms, anxiety, and depression scores were higher. In addition, music students were more perfectionistic. All differences were significant. Effect sizes ranged from small to moderate. Other comparisons, such as hypermobility, core strength endurance, cervical range of motion, and mechanosensitivity, were insignificant .Differences between music students with and without current MHCs (presence of MHCs during the last seven days) at baseline  are given in When comparing music students with current MHCs to music students without current MHCs, pain and physical functioning (both SF12) were significantly increased. In addition, a history of MHCs was more frequent among music students with current MHCs. Music students with current MHCs tended to be more anxious and depressed. However, these findings were not significant. The variables of perfectionism and performance anxiety were not significantly different. Other comparisons, such as hypermobility, core strength endurance, cervical range of motion, and mechanosensitivity, were also insignificant .We recorded 1231 monthly episodes of MHCs  among students in their first academic year . This coThe number of subjects and the predicted probability of at least one monthly episode of MHCs within the first academic year (incidence) are given in p-values of the interaction indicate whether the results of the respective predictor are significantly different between both groups.In students from other disciplines, significant predictors from baseline included reduced mental health, higher mechanosensitivity, and the number of stress symptoms. Increased anxiety and a history of MHCs were also associated with a higher chance of experiencing MHCs over time, although this increase was not significant. In music students, the results were different. Significant predictors from baseline were increased bodily pain, reduced physical functioning, current MHCs, and previous MHCs (four weeks). Furthermore, MHCs ever, MHCs in the previous year, and increased perfectionism were associated with a higher chance of experiencing MHCs over time. In contrast, longer lifetime play was associated with less chance of developing MHCs. However, these findings did not reach significance. Other variables, such as hypermobility, core strength endurance, cervical range of motion, and mechanosensitivity, were also not significant predictors .p-values of the interaction terms indicate, the results of the predictors of mental health, physical functioning, and the number of stress symptoms were significantly different between groups; this suggests a different risk profile in music students compared to students from other disciplines.As the significant The results of the multivariate longitudinal analysis (prediction model) are presented in p < 0.001) and 0.67 (p < 0.001) in students from other disciplines, respectively. The results confirm the presence of different risk profiles between music students and students from other disciplines.The predictive ability of both models is depicted in In this work, we presented the results from a prospective longitudinal study with the overall goal of assessing MHCs and related risk factors in freshmen music students within their first academic year. We analyzed data from six cohorts totaling 146 music students and 191 students from other disciplines. Our cross-sectional analysis revealed that, at baseline, music students were less active in sports compared to students from other disciplines. Physical functioning (SF12) was reduced; pain (SF12) and history of MHCs were higher. Furthermore, mental health (SF12) was decreased, and stress symptoms, anxiety, and depression scores were increased. These findings are in line with other research. Results from a Canadian study sample showed that music students have poorer mental and physical health than non-music controls . FurtherFurthermore, our cross-sectional analysis revealed that music students with current MHCs suffered from pain (SF12) significantly more, their physical function was diminished, and they were more likely to report a history of MHCs compared to music students without current MHCs. In addition, music students with current MHCs tended to be more anxious and depressed. Similar results based on our longitudinal data corroborated this. In music students, single significant predictors at baseline for episodes of MHCs within students’ first academic year were increased physical pain, less physical functioning, the presence of MHCs, and a history of MHCs.Reported risk factors for MHCs from other research studies are only partly in line with our findings. Other studies found previous musculoskeletal injuries or complaints and self-rated health as associated factors with MHCs ,50, whilInterestingly, we found that risk factors for MHCs were different in music students compared to students from other disciplines, leading to the hypothesis that music students and students from other disciplines have distinct risk profiles for MHCs. In students from other disciplines, single significant predictors were poorer mental health, higher mechanosensitivity, and increased stress symptoms. Increased anxiety and a history of MHCs were also positively associated with MHCs over time, but these findings were not statistically significant. Furthermore, a history of MHCs ever, MHCs in the previous year, and increased perfectionism were all associated with a higher chance of experiencing MHCs over time. Significant interaction terms and results from multivariate longitudinal analysis support the assumption of different risk profiles between the two groups. Based on results from the multivariate longitudinal analysis, significant independent predictors for MHCs in music students were current MHCs and reduced physical function, while the final set of significant independent predictors for MHCs in students from other disciplines was a history of MHCs in the previous year and increased stress symptoms. Our results suggest that risk factors for music students are physical-health-oriented, such as bodily pain and physical function, while risk factors for students from other disciplines are more closely related to mental health, such as stress symptoms or anxiety. The presence or history of MHCs is a risk factor common to both of our cohorts. These findings are in line with other research ,52, wherAdditional results from the longitudinal data showed that the probability of MHCs within subjects’ first academic year is substantially higher for music students than students from other disciplines. However, our risk factor analysis results regarding the occurrence of MHCs (monthly records and yearly incidence) cannot be compared to other studies because previous studies were not based on longitudinal data or did not use a similar definition of MHCs ,53. We cA variety of limitations need to be discussed. Thus far, we have investigated MHCs and their corresponding risk factors in a rather general way. We defined MHCs as the perception of any discomfort or impairment within the musculoskeletal system, such as pain/problems, weakness, lack of control, numbness, tingling, or other symptoms. We neither differentiated health complaints within specific parts of the body nor provided a risk factor analysis for specific subgroups of performing artists, such as string instrument or wind players. Here, risk profiles and occurrences of MHCs might be distinct when stratified accordingly, as other research has shown . FurtherFinally, our results may only be valid for freshmen or music students in general. Generalization to other populations of professional musicians, such as orchestra musicians, is unclear, as these were not included in our analysis.The strength of this study lies in the unique nature of our longitudinal study design. This allowed us to prospectively track monthly episodes of MHCs and properly investigate the risk factors. To our knowledge, this study is the first in the field of musicians’ health. Another study with a similar purpose is being conducted at the moment . FurtherThe knowledge of relevant and modifiable risk factors for MHCs, such as current pain and reduced physical function at the beginning of the academic music career, has clear clinical implications for the health of music students. For instance, music students might be screened with respect to underlying risk factors at various stages of their academic career such as at the beginning of their studies and after certain intervals. This helps to identify music students at risk for MHCs at an early stage. Furthermore, knowledge of risk factors forms the basis for the content of targeted, evidence-based prevention programs and rehabilitation. As indicated by our results, such programs should strongly focus on increasing physical function and reducing pain, e.g., providing music students, especially those at risk, with targeted, evidence-based prevention programs alongside their academic career, which might reduce their individual burden of disease, improve their health-related quality of life, and hence optimize practicing time and rehearsals with better health. Thus far, there is little evidence about the effectiveness of specific therapeutic strategies to treat or prevent MHCs. As far as we know, only one single RCT has attempted to assess the effect of a biopsychosocial prevention course tailored to musicians, finding that it was not superior to physical activity promotion in reducing disability from MHCs in music students . This fiHence, for the development of effective prevention programs and rehabilitation, more in depth research is urgently needed. In the future, more prospective longitudinal studies need to be conducted in this field of research to replicate and validate our results. Furthermore, these studies should focus on MHCs of specific parts of the body, such as spinal pain or shoulder complaints, and provide a risk factor analysis for specific subgroups of performing artists. This will help to optimize targeted evidence-based prevention programs and rehabilitation tailored to address specific MHC depending on the type of instrument. Here, risk profiles and consequently prevention strategies are expected to be distinct, e.g., violin players with risk for shoulder pain will require different prevention strategies compared to drum players with risk for low back pain.The results of our prospective cohort study provided new insights into the occurrence and development of MHCs and the corresponding risk factors in freshmen music students. Freshmen music students were at higher risk of developing episodes of MHCs within their first academic year than students from other disciplines. Furthermore, we identified a set of risk factors and a prediction model that implies a distinct risk profile for music students compared to students from other disciplines. Our study results provide the foundation for developing effective targeted and evidence-based prevention programs and rehabilitation, which is crucial for music students, who represent a population that suffers disproportionately from MHCs.


Mentha, Cymbopogon, and Lavandula families and to S. rosmarinus and T. vulgaris species were analyzed, and the performance of several untargeted approaches, based on the synergistic combination of ATR-FTIR and Partial Least Squares Discriminant Analysis (PLS-DA), was tested to classify the species and chemotypes. Different spectra pre-processing methods were employed, and the robustness of the built models was tested by means of a Receiver Operating Characteristic (ROC) curve and random permutations test. The application of these approaches revealed fruitful results in terms of sensitivity and specificity, highlighting the potentiality of ATR-FTIR and chemometrics techniques to be used as a sensitive, cost-effective, and rapid tool to differentiate EO samples according to their species and chemotype.In the present work, the applicability of attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, coupled with chemometric tools in recognizing essential oils (EOs) for routine control, was evaluated. EOs belonging to  Essential oils (EOs) are complex mixtures extracted from aromatic plants by steam distillation or cold pressing. EOs are composed of mono and sesquiterpenes, and their concentrations may extremely vary depending on the type and pedoclimatic conditions of growth of the aromatic plant from where they are extracted . NowadaySalvia rosmarinus and Thymus vulgaris, is extremely affected by the pedoclimatic conditions, leading to different chemotypes of EOs [The EOs of the same genus, and in some cases, also from the same species, might largely vary in the chemical composition. In the latter case, the growth of aromatic plants, such as s of EOs ,6. The is of EOs . Moreoves of EOs . Finallys of EOs .Mentha, Lavandula, and Cymbopogon genus and Salvia Rosmarinus and Thymus vulgaris species were considered for the study, due to their economic importance and large or emerging use in the food industry. Moreover, these EOs were chosen for their variable chemical composition, characterized by high contents of monoterpenes belonging to different classes of organic compounds . First of all, PCA was carried out as an explorative analysis, in order to obtain an overview on the whole data set, without forcing any model and to extract relevant information. PLS-DA was used to create classification models based on ATR-FTIR spectra. Different preprocessed spectra methods were tested, and the predictive ability of the constructed models was assessed by means of internal  and external prediction.However, GC is an expensive and time-consuming method that needs adequate infrastructure related to the use of inflammable and explosive gases. Therefore, the development of new precise, accurate, and rapid analytical methods is required for quickly classifying and evaluating EOs for quality assurance and control. Recently, Rasekh et al., validated a new method for the classification and identification of EOs with the employment of the electronic-nose technology . ConversIn the present work, the raw spectra were employed for the following statistical analyses without any modification. Notwithstanding that ATR spectroscopy induces shifts in the vibrational signals compared to transmission spectroscopy, ATR correction was not performed since all the spectra were acquired in the same manner.The most available EOs on the market, of the Mentha genus, are obtained from the species arvensis (MA), piperita (MP), and spicata (MS). As can be seen in The differences in the composition within the three species could also be observed in the acquired ATR-FTIR spectra . The ass−1 were induced by C=C stretch and C−H out-of-plane bend of terminal vinyl groups, respectively, characteristic of limonene, myrcene, sabinene, and carvone. The intense peaks at 1672 cm−1 and 1644 cm−1 were assigned to the conjugated carbonylic group of carvone. Specifically, the first frequency was related to the C=O stretch, while the second was to the C=C stretch of the conjugated double bond. Finally, the last distinct peak of MS-EO might represent the C−O stretch of the tertiary alcohol α-terpineol at 1110 cm−1.The spectrum of MS-EO appeared extremely different from the others, with several peaks related to functional groups that were not detected in the other spectra. The signals at 3079 and 889 cm−1 represented the O−H stretch of the hydroxyl group of menthol. In the case of menthol-rich MA, the band was shifted at lower frequencies, due to the higher abundance of the alcoholic monoterpene, leading to stronger intermolecular hydrogen bonding [−1 concerning the C−O stretch of secondary alcohols. Finally, the peak at 1708 cm−1 was induced by the C=O stretch of menthone and iso-menthone. The only characteristic band of MP-EO that was not evident in MA-EO concerned the C=O stretch of menthyl acetate at 1737 cm−1.The spectra of both the chemotypes of MA and MP-EO showed the same signals with variable intensity, induced by the different abundance of the same monoterpenes. The peaks at 3418 and 3348 cm bonding . Further2, and –CH3 of alkane chains.The remaining bands, common in all the Mentha EOs, were related to symmetric and asymmetric C−H stretching, bending, and rocking of –CH, −CHSeveral chemotypes have been reported in the literature, based on the analysis of the higher relative percentages of the abundance of certain components ,26,27,28−1, due to C−H out-of-plane bends [The different composition of the four chemotypes was reflected in well-distinct IR spectra , due to ne bends .2 in the monoterpene induced the most intense band in the spectra at 983 cm−1 [−1, particularly marked in cineole-EO, was not identified. Regarding camphor-EO, several peaks in the spectrum were found overlapped with those of cineole-EO but with a minor intensity. The only noteworthy signal was the C=O stretch of the ketone camphor at 1744 cm−1 [−1, while the carbonyl stretch of its ester was not identified, probably due to the presence of camphor stretching at 1734 cm−1. On the contrary, the C−O stretch of bornyl acetate at 1245 cm−1 stood out for its intensity. Regarding verbenone, the signals at 1680 and 1619 cm−1 were attributed to the C=O and C=C stretch of the conjugated carbonyl [In cineole-EO, the key peaks were attributed to the ether group of the monoterpene 1,8-cineole. Specifically, the signals at 1214 and 1079 were representative of C−O−C asymmetrical and symmetrical stretching, respectively. Furthermore, the wagging vibration of CH983 cm−1 . The pea744 cm−1 . Finallycarbonyl .Cymbopogon genus comprises about 180 species, subspecies, varieties, and subvarieties. However, the most important commercial species for the production of EOs are C. martinii (CM), C. citratus (CC), C. nardus (CN), and C. winterianus (CW). These EOs are largely employed in the food, pharmaceutical, cosmetic, and perfume industries as excipients. The chemical composition of the four species analyzed is reported in The C. winterianus species was originated from C. nardus by clonal selection and mutation. The chemical composition of CW and CN EOs was observed to extremely vary within the samples of the same group. Indeed, some EOs exhibited lower content of both citronellol and citronellal, as well as higher content of geraniol and/or camphene. The great variability in the composition might be explained by the fact that these plants can be widely affected by the pedoclimatic conditions of growth [The CM-EOs  were mainly composed by the alcoholic monoterpene geraniol, which ranged between 78 and 88%. In addition, noteworthy concentrations of geranyl acetate and linalool were detected ,33. The f growth ,39,40.Regarding the ATR-IR spectra, great differences within palmarosa, lemongrass, and java EOs were highlighted. On the contrary, as expected by observing the GC results, important dissimilarities between CW and CN were not identified . The mai−1 were induced by the primary O−H stretch, C=C stretch, C−C stretch and C−O stretch, respectively [−1 was assigned to the carbonylic stretch of geranyl acetate. The main signals in the spectra of CC-EOs were linked to the conjugated aldehydes, neral and geranial. Specifically, the peaks at 2763, 1671, 1632 (and 1612) cm−1 were related to aldehydic C−H stretch, conjugated C=O stretch, and conjugated C=C stretch, respectively [−1 were tentatively assigned to the conjugated aldehyde C−C stretch.The spectra of CM-EOs were mainly characterized by the signals of geraniol. In particular, the peaks at 3325, 1669, 1233, and 998 cmectively . Additioectively . The fur−1, induced by citronellol and geraniol. Moreover, the saturated aldehyde citronellal caused the vibrations at 2722 and 1725 cm−1, due to the aldehydic C−H and C=O stretches [Finally, the spectra of CW and CN-EOs exhibited the characteristic signals of primary alcohols at 3412, 1233, and 998 cmtretches ,25.Lavandula genus is mainly represented by the most diffuse species L. angustifolia (LA), L. x intermedia (LI), and L. latifolia (LL). The composition of LA and LL-EOs were shown to differ in the content of several mono and sesquiterpenes, such as 1,8-cineole, linalool, camphor, and linalyl acetate. On the contrary, LI-EOs, L. x intermedia being a hybrid plant between L. angustifolia and L. latifolia, displayed an intermediate composition , and 1019 cm−1. The C=O stretch of carbonylic groups of bornyl acetate and camphor were present at 1735 and 1717 cm−1, respectively. The hydrocarbon camphene exhibited the vibration at 876 cm−1 linked to vinylidene C−H out-of-plane bend.Borneol-EO mostly differed for the vibrations of the alcohols borneol, carvacrol, and α-terpineol, the ketones camphor and carvone, and the hydrocarbon monoterpene camphene. In particular, the alcohols induced the O−H stretch at 3371 cm−1, vinyl C−H stretch at 3088 cm−1, and vinyl C−H out-of-plane bends at 919 cm−1 related to alcohols and terminal double bonds, respectively.Finally, linalool-EO showed the characteristic O−H stretch at 3402 cmThe PCA was applied to the whole data matrix  to have a general overview of the trend, similarities, and differences among the investigated samples, according to their IR profiles. The PCA is commonly used to summarize the information included into datasets by extracting new artificial variables called principal components (PCs). These new variables intrinsically carry the information of the original variables, extrapolating the most important underlying information of the dataset. By projecting samples onto the first few PCs, the structure of the investigated data can be visualized into a lower-dimensional space. PCA is strongly recommended prior to supervised classification methods , with it being an informative predictor to comprehend whether reliable PLS-DA models might be trained on the data .2: 81%).Four principal components were considered according to their explained variances , and at 1214, 1080, and 985 cm−1 induced by 1,8-cineole. Besides, lavender EOs were conditioned by the peaks at 1375–65 cm−1 of the tertiary alcohol linalool, and at 1466 cm−1 that was not previously identified. This latter signal might belong to frequencies of saturated aliphatic groups [−1 played a central role in collocating the remaining EOs in negative on PC1. Lavender EOs were predominantly clustered by their typical peaks at 1738, 1370, 1244–1239, and 917 cm−1 , which gained the highest positive loadings on PC3. Finally, thyme EOs were positively separated from the remaining EOs, due to the high loadings on PC4, attributed to bands at 1516, 1419, 1289, 945, and 813 cm−1 related to p-cymene and thymol, as well as 1154 cm−1 induced by borneol. Furthermore, the absence of characteristic signals in the regions at 1745–1678 and 1045–993 cm−1 influenced the scores of these EOs, being important variables with negative loadings on PC4.The different EOs are represented with different symbols and colors depending on their genus. Each component seems to slightly differentiate samples belonging to one class of EO. In particular, rosemary EOs got the highest scores for PC1, lavender for PC3, and almost all thymes for PC4. As far as PC2 is concerned, this component mainly highlighted differences within citronella and mint EOs. Indeed, only some EOs of these classes presented higher PC2 score values, showing different IR signals with respect to the other samples. Notwithstanding that the aim of the present study is to build a fast model able to extract information about the differences among the investigated EOs in an untargeted manner, some considerations on the presence of some chemical compounds can be done by looking at the loading plots of the selected PCs. From the loading plots of the PCs, displayed in c groups . On the −1 and at 889 cm−1 which induced a split of the classes. These vibrations corresponded to conjugated carbonyl groups belonging to ketones and aldehyde  typical of MS and CC-EOs that were notably different from the EOs from the same genus. Additionally, the frequencies at 1435–1365 and 1114 cm−1, belonging to saturated aliphatic groups and α-terpineol (present in MS-EOs), had a moderate role in the separations of Mentha e Cymbopogon classes.On the contrary, Mentha and Cymbopogon EOs were not completely separated. These latter EOs were partially influenced, instead, by the elevated PC2 loadings in the range 1672–1632 cmMentha, Cymbopogon, and Lavandula genus. As far as chemotypes of Thymus vulgaris is concerned, it was not possible to build a classification model for each genus, due to the low number of samples. However, for this genus, a preliminary PCA showed a good differentiation among the different chemotypes , standard normal variate (SNV) + MC, multiplicative scatter correction (MSC) + MC, Savitzky–Golay first derivative (1st der) + MC, and Savitzky–Golay second derivative (2nd der). With regards to the first and the second derivatives, second order and third order polynomials, with seven points in each window, were used, respectively. The obtained results of PLS-DA models, using different pretreatments , are reported in In all the developed models, the permutation results were lower than 0.05, indicating that the randomly permuted models were significantly different at the 95% limit, highlighting the clear robustness of the obtained classification models. Furthermore, it is worth noting that almost all the models presented a high accuracy since all AUC values were higher than 0.92; indeed, the closer the value of the AUC is to 1, the better the classification model. However, slight differences emerged in terms of sensitivity (percentage of objects belonging to the class correctly accepted by the class models) and specificity (percentage of objects not belonging to the class correctly rejected by the class model) in both CV and prediction models.Salvia Rosmarinus achieved 100% in sensitivity and specificity, all other models showed a good performance, pointing out the potentiality of ATR-FTIR to detect chemical distinction among the different species. By examining the variable importance in projection (VIP) score plots in depth  seemed to be the most efficient pretreatment methods in this research. However, first derivatives + MC pretreatments could be chosen since the respective models seemed to be more parsimonious, selecting a lower number of latent variables. Although only the three classification models of in depth , it was Mentha, Lavandula, and Cymbopogon genus, as well as the Thymus vulgaris and Salvia Rosmarinus species.Finally, to have a general overview of the performance of the PLS-DA-assisted untargeted ATR-FTIR approach, PLS-DA was performed on the whole data set simultaneously, considering all the data acquired on samples belonging to five classes: namely, For building the model, 218 samples were used for calibration and 120 for external validation, and, based on the previous results, the signals were pretreated with Savitzky–Golay first derivative (1st der) + mean centering. The number of samples belonging to each class, for training and external validation sets, was reported in The number of latent variables for PLS models was chosen by the smallest mean squared error obtained in CV (venetian blind with 10 data splits).The best EOs classification model was built with six latent variables, and this model gave excellent results in terms of robustness and classification performance .Thymus vulgaris species, classified as Lavandula in both CV and prediction models. This result might be due to the close chemical composition of certain thyme EOs displaying the linalool chemotype.In particular, the model showed excellent sensitivity in both CV and prediction models, with all the samples correctly classified in the respective belonging class. As far as specificity is concerned, all the EOs not belonging to the class were correctly rejected by the class model except for two samples belonging to the −1 and 2000–500 cm−1. These regions were already highlighted as relevant by inspecting PCA loadings. The variables with the highest scores were strictly related to characteristic IR signals present in most of the EOs belonging to the same class, as expected. Indeed, for Mentha EOs, the most discriminating variables were related to ketones , menthol vibrations (1100–1000 cm−1) and monoterpenes containing terminal vinyl groups . Similarly, S. Rosmarinus EOs were mostly represented by ketones  and the heterocyclic monoterpene 1,8-cineole (1085 and 980 cm−1), while Lavandula EOs were represented by the stretch and bends of the carbonylic group of linalyl acetate (about 1740 and 1240 cm−1) and the hydroxyl group of linalool (1375–1365 cm−1). Cymbopogon EOs, being mainly composed of aldehydes and alcohols, were predominately projected by the variables around 1730–1600 and 1380 cm−1. Finally, concerning T. vulgaris EOs, the highest scores were reached by several variables in all the fingerprint regions, being the most variable in composition due to the expression of several different chemotypes. In particular, the signals belonging to alcohols , ketones (carvone and camphor), phenols (thymol), and hydrocarbons (p-cymene and camphene) contributed to the classification model.The VIP score plots  showed tThe diversity of chemical composition and, then, functions of EOs belonging to the same genus or chemotype offers a great variety of applications. However, in some cases, certain compounds of EOs can also display features such as allergenicity or toxicity. Therefore, qualitative controls of EOs are certainly an important issue. The key technique for the identification of the type of EOs is the GC, where quantitative results of the chemical compounds allow the recognition by comparing the composition with reference monographs . AlternaOcimum EOs was attempted by Freitas et al., on NMR spectra and GC chromatograms, demonstrating the excellence of the NMR approach in recognizing the species [The creation of PLS-DA models for  species . CertainMentha arvensis (MA), Mentha spicata (MS), and Mentha piperita (MP) were collected. On the label of all these samples, the species was specified by the producing/seller company. A total of 38 Salvia rosmarinus EOs was collected. The chemotype of the EO was not reported in the majority of the labels. A total of 35 EOs, belonging to Cymbopogon winterianus (CW), Cymbopogon nardus (CN), Cymbopogon citratus (CC), and Cymbopogon martinii (CM) were obtained. On the label of all these samples, the species was specified by the producing/seller company. Thirty EOs, belonging to Lavandula latifolia (LL), Lavandula x intermedia (LI), and Lavandula angustifolia (LA), were investigated. On the label of all these samples, the species was specified by the producing/seller company. Finally, a total of 32 Thymus vulgaris EOs were collected. The chemotype of the EO was not reported in the majority of the labels. n-Hexane and the mixture of aliphatic hydrocarbons (C8–C40) were purchased from Sigma-Aldrich .All the EOs were kindly donated by several companies fully cited in the acknowledgments. A total of 36 EOs belonging to the n-hexane before GC-MS analysis.Analyses were performed on a 7890A gas chromatograph coupled with a 5975C network mass spectrometer (GC-MS) . Compounds were separated on an Agilent Technologies HP-5 MS cross-linked poly−5% diphenyl–95% dimethyl polysiloxane  capillary column. The column temperature was initially set at 45 °C, then increased at a rate of 2 °C/min up to 100 °C, then raised to 250 °C at a rate of 5 °C/min, and finally, it held for 5 min. The injection volume was 0.1 μL, with a split ratio 1:20. Helium was used as the carrier gas, at a flow rate of 0.7 mL/min. The injector, transfer line, and ion-source temperatures were 250, 280, and 230 °C, respectively. MS detection was performed with electron ionization at 70 eV, operating in the full-scan acquisition mode in the m/z range 40–400. The EOs were diluted 1:20 (v/v) with 8–C40) were diluted 1:20 (v/v) with Hex before GC-FID analysis. Helium was used as the carrier gas at a flow rate of 1 mL/min. The injector and detector temperatures were set at 250 and 300 °C, respectively. EO components were separated on an Agilent Technologies HP-5 crosslinked poly−5% diphenyl–95% dimethylsiloxane  capillary column. The column temperature was initially set at 45 °C, then increased at a rate of 2 °C/min up to 100 °C, then raised to 250 °C at a rate of 5 °C/min, and finally, it maintained for 5 min. The injection volume was 1 μL, with a split ratio 1:20.Chromatographic characterization of EOs was performed on a 7820 gas chromatograph  with a flame ionization detector (FID). EOs and the mixture of aliphatic hydrocarbons (CLRIs) relative to C8–C40n-alkanes obtained on the HP-5 column, under the above-mentioned conditions, with the literature [Compounds were identified by comparing the retention times of the chromatographic peaks, with those of authentic reference standards run under the same conditions, and by comparing the linear retention indices  software.−1, with a spectral resolution of 4 cm−1, averaging 16 scans per spectrum. The number of scans was selected for the optimal signal-to-noise ratio. The background spectrum of the empty ATR cell was obtained under the same instrumental conditions prior to the sample analysis. All samples were analyzed in duplicate.The ATR-FTIR spectra of the EOs were obtained using a FT-IR spectrometer Spectrum Two, equipped with a Universal ATR sampling accessory . One drop of each sample was deposited on the ATR diamond crystal cell. The spectra were acquired in the spectral range of 4000–450 cm−1  were exported to create the datasets.For each EO, the absorbance percentages related to each wavenumber in the infrared range from 4000 to 450 cm®. The PCA was performed on all the ATR-FTIR spectral data. All the IR signals were organized in a bidimensional matrix of dimension 338 × 3551  and pretreated by means of multiplicative scatter correction (MSC), followed by mean-centering. In this first step of exploratory analysis, MSC pretreatment was selected to minimize additive and multiplicative effects present in the baseline of the spectral data. The number of PCs was selected based on the best compromise between the smallest root mean squared error in leave one out cross-validation (RMSECV). A detailed investigation on the right choice of the signal pretreatment to be used was performed during PLS-DA analysis.The multivariate statistical analyses were performed by using PLS_Toolbox 8.9.2 software  for MATLABThe PLS-DA can be defined as a multivariate technique that allows the creation of discrimination models, giving the maximum covariance between measured data  and the response variable  . For bui2 plot  curve was used to have an overall picture of the classification performance and, together with permutation tests, was carried out to be sure to obtain trustworthy results . RegardiOn the other hand, an iterative permutation test involves a random distribution of y-block assigning, at each sample, an incorrect class. Afterwards, different classification models are calculated, and if the performance of these models are significantly and systematically lower than those obtained with the original one, the original model can be assumed to be robust.Finally, since the sensitivity and specificity values equal to 100% could increase the probability of overfitting, a classification model was also built with a lower number of LVs. In particular, for the whole EOs dataset, 5 LVs were considered, as they presented the second best compromise in terms of classification error average both in calibration and cross-validation . The obtLavandula and Cymbopogon genera due to the almost identical chemical compositions of some species. The AUC values were higher than 0.92, suggesting the robustness of the classification models. Due to the small number of thyme EOs, the PLS-DA models were not performed, while in the case of rosemary EOs, the models were constructed by combining two different chemotypes. However, preliminary unsupervised PCA was carried out on each dataset, depicting the capability of multivariate statistical tools to differentiate rosemary and thyme EOs, depending on their chemotype (In the present work, ATR-FTIR spectroscopy was demonstrated to efficiently highlight the differences in the chemical composition of EOs belonging to valuable and extremely different genus and species. The PLS-DA models, built on the spectral dataset processed through the first derivative and mean centering, showed excellent predictive performances in terms of specificity and sensitivity, correctly classifying the majority of EOs. The misclassified EOs belonged to hemotype . In conc


Health sciences students experience high levels of psychopathology conditioned by psychosocial, financial, and academic factors. However, COVID-19 pandemic might even have worsened their mental health. Thus, this article aims to evaluate how the exposure to COVID-19 pandemic has affected these students’ mental health and to determine the effect of purpose in life and character strengths on this psychopathology.A cross-sectional study of unpaired samples was carried out in Spain during the first and third waves of the pandemic in 70 medical and 52 nursing students.p < 0.001), while the most protective factors were honesty  and purpose in life . Purpose in life also protected against the onset of depression and total psychopathology. In addition, we observed studying medicine was a protective factor against total psychopathology while being a nursing student was associated with high levels of acute stress.The risk factor that most determined the appearance of anxiety was the exposure of family and friends to COVID-19 (OR = 4.01; Exposure of the students’ family and friends to SARS-CoV-2 favored the appearance of symptoms of anxiety. Honesty had a preventing role in the onset of anxiety and a high purpose in life was protective against the appearance of anxiety, depression, and total psychopathology. Studying health sciences acts as a risk factor for developing psychopathology, such as anxiety, depression, acute stress and alcohol or substance abuse . StartinDuring their academic training, medical, and nursing students experience high levels of distress which is conditioned by psychosocial, financial, and academic factors –5. This A recent analysis carried out by the State Council of Medical Students (CEEM in its Spanish acronym) concluded that up to 41% of medical students presented at least one sign of depression, and 24.7% experienced high levels of anxiety . In the As seen, anxiety, depression, acute stress, and alcohol or substance abuse are considered very prevalent conditions in health sciences students. Because of this, an attempt has been made to identify possible predisposing factors so that effective prevention measures can be implemented . In thisAmong university careers, medicine and nursing are two traditionally vocational choices, a fact that the virus has significantly highlighted . StudentResearch has been published on the psychopathological consequences of COVID-19 in students in general , but no t-test. For an effect of 0.5, with an alpha of 0.05, power of 0.80, and an N2/N1 allocation ratio of 1.3, a group size of minimum 59 for group 2 (medicine) and 45 for group 1 (nursing) would be required , so the sample recruited  is sufficient. The data were collected between 20 April and 27 May 2020 (2019–2020 academic year) when Spain was immersed in the peak of the first COVID-19 wave, and between 4 December 2020 and 19 January 2021 (2020–2021 academic year) during the third wave, with the latter having had the greatest generalized impact on society , respectively. Drug abuse was assessed using the Drug Abuse Screening Test (DAST-10) , Beck’svalidity ] and alcvalidity ; reliabivalidity ].Variables that evaluated the different types of exposure to COVID-19  were considered as independent variables. A 2 item Likert like questionnaire used in a previous study  was admiSPSS software (version 27) for Microsoft  was used for all the statistical analyses. After the exploratory  and descriptive study, the variables were subsequently compared using Student’s t-distribution for quantitative variables and Pearson chi-squared tests for categorical variables. Linear regression models were created for the psychopathological variables, introducing exposure to SARS-CoV-2, PIL, character strengths and moral courage as independent variables. Finally, the data were modeled using the PROCESS plugin (v3.4) for SPSS .The ethical principles set out in the Declaration of Helsinki and by the Council of Europe Convention were followed and the informed consent of all participants was obtained. Moreover, data confidentiality was guaranteed according to the General Data Protection Regulation . This study was authorized by the Investigation Commission at the Provincial Hospital Consortium in Castellon (ref. A-15/04/20) and the Clinical Research Ethics Committee of the Cardenal Herrera-CEU University (ref. CEI20/068).2 = 6.556; p = 0.010). Significantly more students in the medical student group were single  while more were married in the nursing student group . Finally, there were significantly less smokers in the medical student group  than in the nursing student group   .M = 5.87; SD = 1.382 vs. M = 6.38; SD = 0.844; t = 2.535; p = 0.013) and about teamwork . In addition, we observed significantly higher PMCS score among medical students  than in nursing students .M = 8.24; SD = 7.767 vs. M = 11.19; SD = 8.381; t = 2.005; p = 0.047) and less presented an anxiety disorder . Medical students  also had lower ASD scores than nursing students  and a lower proportion of ASD . Finally, medical students  had less psychopathological symptoms than nursing students .In terms of psychopathology , comparep < 0.001), PIL , spirituality , and honesty  all directly affected BAI. In addition to a direct effect on anxiety, PIL also had an indirect effect through honesty , while spirituality had an indirect effect through PIL itself .Finally, This is the first work to evaluate the effect of the COVID-19 pandemic on the development of psychopathology in health sciences students while also considering the effects exerted by PIL, character strengths and moral courage.In our work the more exposure of family and friends of the health science students, the greater their risk of developing anxiety. Recent studies have shown that exposing family to COVID-19 was the main reason why healthcare workers did not go to work , being aPrevious studies have already shown the ability of PIL to positively moderate the prevention of psychiatric disorders , 35. A hOn the contrary, intense spirituality is associated with lower subjective wellbeing in medical students  and can Opposite to prior studies , no signTo sum, our work indicated that anxiety levels can predicted by the degree of family and friends’ exposure to SARS-CoV-2, PIL, honesty and the students’ level of spirituality .Our research showed that nursing students had a higher incidence of anxiety, acute stress and total psychopathology, as seen prior to the pandemic . In factThis theory would be reinforced by the finding that occupation (nursing) can predict high levels of acute stress and the better results for GACS-24 teamwork and love item obtained by nursing students. As an alternative hypothesis, medical students may have greater social desirability than nursing students meaning that they therefore tend to minimize psychopathology. Indeed, previous studies have shown an inverse relationship between social desirability and psychopathology . HoweverTherefore, it is advisable to pay attention to the education of health sciences students as it could affect their future mental health. Likewise, not addressing the psychopathology they present as students would have a negative impact on their future job performance . One wayFinally, we must mention the main limitations of this study. Firstly, this work was carried out at a single Health Sciences Faculty, which may reduce its external validity compared to multicenter studies. Secondly, when weighing up the impact of the COVID-19 pandemic we must consider the cumulative incidence in each region or country, which was lower in the province where the study was carried out compared to other areas in Spain and other countries. Sociodemographic differences between both groups of students should also be considered because these could influence the presence of psychopathology. Thirdly, because of the cross-sectional nature of this study, we cannot state with certainty that the psychopathological results we found responded exclusively to the COVID-19 pandemic and the predictor variables. The intentional sampling used in the recruitment should also be considered as a possible methodological weakness.This study shows that the COVID-19 pandemic impacted the development of psychopathology in health sciences students. Specifically, exposure of the students’ family and friends to SARS-CoV-2 favored the appearance of symptoms of anxiety. Studying medicine was a protective factor against total psychopathology while being a nursing student was associated with high levels of acute stress. In contrast, honesty had a preventing role in the onset of anxiety and a high PIL was protective against the appearance of anxiety, depression, and total psychopathology.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving human participants were reviewed and approved by the Investigation Commission at the Provincial Hospital Consortium in Castellon (ref. A-15/04/20) and the Clinical Research Ethics Committee of the Cardenal Herrera-CEU University (ref. CEI20/068). The patients/participants provided their written informed consent to participate in this study.IE, AB, and GH: conceptualization. IE and IA: data curation. AB: formal analysis. MP, DP, and VQ: investigation. IE, MP, DP, and VQ: draft preparation. IE, MP, DP, VQ, AB, IA, and GH: review and editing. GH: funding acquisition. All authors have read and agreed to the published version of the manuscript.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Over the past decades, the optimum protein intake for patients with chronic kidney disease (CKD) has been an important, controversial issue. Dietary protein restriction has been commonly recommended for patients with CKD for preserving kidney function. However, evidence of the associations between long-term protein intake and mortality is not consistent in patients with CKD. Therefore, we aimed to examine the associations between total protein intake and all-cause mortality in Korean adults with CKD.2 (CKD stage 3–5) were included in this study. Dietary data were collected using food-frequency questionnaires at baseline. Deaths were followed from 2001 to 2019. Cox proportional hazards regression model was used to evaluate the association between protein intake and all-cause mortality.From three sub-cohorts of the Korean Genome and Epidemiology Study (KoGES) starting from 2001, total 3,892 participants with eGFR < 60 mL/min/1.73 mDuring a median follow-up (min-max) of 11.1 years (0.3–15.1), 602 deaths due to all causes of mortality were documented. After adjustment for covariates, higher total protein intake was not associated with all-cause mortality  in CKD stage 3–5 patients.Dietary protein intake was not associated with mortality from all causes in patients with CKD. Further research is needed to establish optimal protein intake levels and examine the impact of the dietary source of protein on various health outcomes and mortality in CKD. Chronic kidney disease (CKD) is a progressive condition characterized by a gradual loss of kidney function, causing kidney damage over time . Over thAlthough genetic factors play an important role in the incidence and progression of CKD, most cases are attributed to nutritional factors and are largely preventable . TherefoIn recent years, several clinical studies and meta-analyses have proved the effectiveness of a low protein diet (LPD) on kidney outcomes , 13–15. However, despite the available evidence on the benefits of protein restriction, the renoprotective effect of LPD has been debatable due to conflicting results , 17. MorThere are substantial differences in dietary habits, food selections, and cooking methods between various populations. The typical American diet contains approximately twice the protein intake recommended by US dietary guidelines . Accordi1This study used data from population-based cohorts in the Korean Genome and Epidemiology Study (KoGES), including the KoGES_Ansan and Ansung study , the KoGES_health examinee study (HEXA study) , and the KoGES_cardiovascular disease association study (CAVAS study) . In the KoGES, men and women aged over 40 years were recruited for the baseline survey. In the KoGES_Ansan and Ansung study, a total of 10,030 participants aged 40-69 years were voluntarily enrolled at baseline between 2001 and 2002. In the KoGES_HEXA, a total of 173,357 participants were enrolled at baseline from 2004 to 2013. In the KoGES_ CAVAS, a total of 28,338 participants were enrolled at baseline from 2005 to 2011. Detailed information about KoGES were provided in the following website and a previous study .1n = 2,231), laboratory tests , and nutritional intake , along with implausible daily total calorie intake  who report energy intake levels at the low and high ends of the spectrum  was calculated as body weight (kg) divided by square of height (m). Waist circumference was measured using the measuring tape at the midline level between the inferior margin of the ribs and the superior border of the iliac crest. Smoking status was categorized into current smokers, former smokers, and non-smokers. A current smoker was defined as any participant who currently smoked and has smoked at least 100 cigarettes during their lifetime. Former smokers were defined as adults who smoked at least 100 cigarettes in their lifetime and had quit smoking. Never smokers were defined as adults who had never smoked or smoked < 100 cigarettes in their lifetime. The status of alcohol intake was categorized into current drinker, former drinker, and non-drinker. A regular exerciser was defined as a person who regularly engaged in exercise that is enough to sweat more than once a week. Hypertension was defined as a systolic blood pressure of ≥ 140 mmHg, diastolic blood pressure of ≥ 90 mmHg, or those taking antihypertensive medications. Diabetes was defined as a glycated hemoglobin level of ≥ 6.5%, fasting plasma glucose concentration of ≥ 126 mg/dL after a ≥ 8 h fast, or those taking anti-diabetic medications. Dyslipidemia was defined as a total cholesterol level of ≥ 200 mg/dL, triglyceride ≥ 150 mg/dL, or those taking anti-dyslipidemia medications.2 , including death records, to evaluate mortality status. Participant deaths were tracked from January 2001 until December 2019. The underlying causes of death were based on the Korean Standard Classification of Diseases codes listed in the National Death Index. All-cause mortality was defined as all deaths of specified and unknown causes.Information on nutritional intake was derived from the FFQ data. In 2001, a semi-quantitative food frequency questionnaire (FFQ) containing 103 food items was developed for the KoGES survey . Each quDetailed information regarding the protocol and results of a validation study for the FFQ have been described in the previous studies , 28. AftData were analyzed from 2001 to 2013. Participant deaths were tracked until December 2019. The follow-up period for each study participant was calculated as the time from their KoGES initial assessment to either an event of mortality or the date of death. Data were presented as mean ± standard deviation (SD) for continuous variables or number (%) for categorical variables. Protein intake (g/kg/day) was divided into quintiles. Baseline characteristics of the study population according to the protein intake quintiles were compared using the one-way analysis of variance (ANOVA) for continuous variables and the Chi-squared test for categorical variables. A Cox proportional hazard spline curve was used to assess the association between dietary protein intake and all-cause mortality risk. Warranty period was defined as the time to reach the cumulative mortality rate of > 1% for each group. Person-time is an estimate of the actual time-at-risk in years. Incidence per 1,000 person-years was calculated for each group. Cox proportional hazards regression model was used to evaluate the association between protein intake and all-cause mortality. We adjusted for covariates in 3 models. Model 1 was adjusted for age, sex, and BMI. Model 2 was adjusted for age, sex, BMI, smoking, alcohol intake, exercise, and total calorie intake . While model 3 was further adjusted for hypertension, dyslipidemia, and diabetes. We performed sensitive analysis to investigate the protein intake and mortality in CKD patients according to presence of diabetes and total calorie intake 20 kcal/kg/day criteria.2 All statistical tests were two-sided, and P < 0.05 was considered statistically significant.We used SAS version 9.4  and R package version 4.0.3.P < 0.001), with a lower BMI, waist circumference (P < 0.001), and triglyceride levels (P < 0.001). They were more likely to drink alcohol and exercise regularly (P < 0.001) and were more likely to live in urban areas (P < 0.001), as compared to the lower protein intake group. There were no significant differences in blood pressure and glucose levels, glycated hemoglobin, total cholesterol, and LDL cholesterol. Regarding underlying disease, the proportion of patients with dyslipidemia was significantly higher in the lowest protein intake group than the highest protein intake group. The proportion of those with hypertension and diabetes was not significantly different between the two groups. Regarding nutritional intake, total calorie intake, carbohydrate intake (g/day), and fat intake (g/day and %) were significantly higher in participants with a higher protein intake than in those with lower protein intake. The proportion of carbohydrate intake (%) was significantly lower in patients with CKD with higher protein intake than in those with lower protein intake. The results from the post hoc analysis between the quintiles based on dietary protein intake are shown in Baseline demographics, lifestyle, and nutrient intake were organized according to quantiles of total protein intake (g/kg/day) and are presented in We performed several sensitivity analyses. We examined the association between total protein intake and all-cause mortality in patients with CKD according to the presence of diabetes . There wIn this large population cohort of Korean adults with CKD, we found that higher protein intake was not associated with all-cause mortality. Additionally, we observed similar results after stratifying based on CKD stages and the presence of diabetes.Given the high incidence of CKD and an emergent need for disease management strategies, lifestyle and dietary modifications are cost-effective strategies that may help increase the lifespan and prolong the dialysis-free interval in treating patients with CKD . Althoug2 , which remains substantially higher than the recommendations of LPD for patients with CKD; however, it is not clear whether the benefit of protein restriction is warranted in view of the potential for causing malnutrition . Under p2 . Therefo2 , protein2 , 48. Pro2 . Conside2 , 51, exc2 , 53.While interpreting our findings, protein food sources and the dietary pattern of the Korean diet should be considered. The main characteristic of the Korean diet includes proportionally high consumption of vegetables, moderate-to-high consumption of legumes and fish, and low consumption of red meat . Accordi2. Forth, the lack of information on dialysis made it impossible to analyze the effect of dietary protein on mortality by categorizing patients with CKD based on their dialysis requirements. Instead, we conducted sensitivity analyses according to the CKD stages to test the robustness of our results, and there were also no significant associations between total protein intake and all-cause mortality in each stage. However, the KoGES contains very few individuals with advanced CKD; hence further studies specifically targeting advanced patients with CKD and patients on dialysis are needed. Fifth, to clarify the association between dietary total protein intake and mortality in CKD patients, validation is needed in the other larger CKD cohort. Finally, we could not further explore the effect of dietary protein on mortality by specific causes due to the limited number of patients who died. Despite these limitations, this study has several strengths. Our study comprised a prospective design, a large population size, and an extensive, eleven-year follow-up period. Also, to our knowledge, this is the first study to examine the association between total protein intake and mortality risk among adult patients with CKD in an Asian population.Our study has several limitations. First, the amount of dairy protein intake was assessed using FFQ, which has disadvantages, including inaccuracy of absolute nutrient values and fluctuation of nutrient values. However, FFQ is a validated, relatively cost- and time-effective method to assess nutrient intake and to assess usual and long-term intake in large-scale epidemiologic studies , Second,We could not confirm a causal relationship between dietary protein intake and survival in the Korean population with CKD. Higher protein intake was not associated with all-cause mortality in patients with CKD, and similar results were obtained after stratifying patients based on CKD stages and the presence of diabetes. Based on these findings, our analysis supports that severe protein restriction with less severe kidney failure may not have a clear beneficial effect for all-cause death events. Further research is needed to establish optimal dietary protein intake levels for this population with CKD stage 3–5. Also, additional studies are needed to examine the impact of the dietary source of protein on various health outcomes and mortality.The original contributions presented in the study are included in the article/The studies involving human participants were reviewed and approved by the Yongin Severance Hospital. The patients/participants provided their written informed consent to participate in this study.Y-JK, HL, GP, and J-WL contributed to the conception or design of the work. Y-JK, HL, GP, H-MK, WK, JL and J-WL contributed to the acquisition, analysis, and interpretation of the data, draft the manuscript. All authors critically revised the manuscript, provided final approval and agreed to be accountable for all aspects of the work, ensuring integrity and accuracy.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Achilles tendinopathy (AT) is one of the most frequent overuse injuries in the ankle. The evidence base for its conservative management AT continues to evolve, but there is still a gap in the evidence for the efficacy of any modality of treatment in high-quality studies. This systematic review and meta-analysis investigated the efficacy of EE in improving pain and function in adult patients with mid-portion Achilles tendinopathy compared to other forms of exercise. A search was performed in PubMed, BIREME, SportDiscus, Cinahl, Web of Science and PEDro, in November 2022. The methodological quality was evaluated using the Risk of Bias 2 tool (RoB2) of the Cochrane collaboration, and the meta-analysis was performed using the Review Manager 5.1 program. 2024 articles were identified and eight fulfilled the inclusion criteria. RoB2 presented a final score with 62.5% of the studies presented “some concerns”, and 37.5%  presenting “high risk” of bias. EE was effective for the managment of AT. The only variable for which a meta-analysis was possible was pain (five articles), analysed with the visual analogue scale/numerical visual scale. The mean difference (MD) in treatment effect using EE was − 1.21 (− 2.72 to − 0.30) with a 95% of confidence interval (CI), thus identifying a significant positive effect for the improvement of pain in patients with AT in whom EE was used. EE is effective in the management of AT. The meta-analysis shows the need for appropriately powered randomized controlled trials with better design, the use of standard outcome measures and well-planned protocols for conservative management of AT.Level of evidence: Level 1.Registration: CRD42018118016. The Achilles tendon is one of the widest and strongest tendons in the human body. Despite this, injuries are common . AchilleAT has an incidence of 1.85 per 1000 people in the general population . Most inBasketball, soccer, tennis and wrestling have high incidence rates of ankle injuries , 11. Up Abnormal biomechanics of the lower limb may increase the risk of excessive or unusual loading of the Achilles tendon, and changes in range of motion (ROM) of the ankle and lower limb have been associated with an increased risk of AT . In mostConservative therapies for the management of AT include kinesiotherapy, electrotherapies, cryotherapy, dry needling, bandaging, splints–21. ExerIn eccentric exercise, the muscle contracts while being lengthened . EccentrThe prognosis of AT may vary from individual to individual. Paavola et al., in a 8-year follow-up study, showed that 84% of the patients returned to their pre-disease activity levels, and 94% of the patients were asymptomatic or had only minimal pain .The evidence base for conservative therapy for AT continues to evolve, but there is still a gap in the evidence for its effectiveness in high-quality studies. We performed a systematic review and meta-analysis to investigate the efficacy of EE in improving pain and function in adult patients with mid-portion Achilles tendinopathy compared to other forms of exercise.The protocol for this review was registered in the International prospective register of systematic reviews—PROSPERO, number CRD42018118016, the PRISMA guidelines  and the AMSTAR 2 (A MeaSurement Tool to Assess systematic Reviews) were used.The search was performed in PubMed, BIREME, SportDiscus, Cinahl, Web of Science and PEDro without date restriction filter. Table Following identification of the articles which matched the inclusion and exclusion criteria, their references were manually searched to identify other possible articles to be included in the present study.As randomized clinical trials (RCT) are the gold standard to assess the effectiveness of clinical research , we inclWe did not include studies reporting on participants with ruptured Achilles tendon or with insertional tendinopathy. The search was limited to human studies and published in Portuguese, English or Spanish, due to the language capabilities of the researchers. In addition, review articles, expanded abstract, letters to the editor, annals of congress, editorials, dissertations and theses were excluded.The following information was extracted: basic information ; and outcome measures . The search was performed by two researchers independent of each other. If there was disagreement, a third reviewer was consulted for final decision. Data were exported and stored in the Zotero® program, where duplicate articles were excluded. The data were then exported to Microsoft Excel®, where articles were removed according to their titles, followed by their abstract, and then the remaining articles were read in full text. Relevant data were then extracted manually and inserted into Review Manager software (RevMan 5.3).The Cochrane Collaboration risk-of-bias 2 (RoB 2) tool for randomized trials was used to assess the risk of bias in the included studies . The toop value and I2. If p > 0.10 and I2 < 50%, the heterogeneity was considered low enough to conduct a meta-analysis with a fixed-effect model. If p < 0.10, I2 > 50%, there was a high level of heterogeneity, and a random effect model was used. Sensitivity analysis was conducted by one-by-one exclusion method for individual studies. Descriptive analysis was performed if the heterogeneity was too large (I2 > 85%).A meta-analysis was performed to synthesize study data and verify the effect size of the intervention using the RevMan 5.3 program. The results of the meta-analyses are presented in a forest plot, where the left side positively represents the treatment (less than zero) and the right side negatively (greater than zero). We used for the meta-analysis an effect model with a justification of the same AT population, and a mean difference as the type of effect size. Each study is shown with its effect size and the corresponding 95% confidence interval , 38. TheA total of 2024 articles were identified among the published articles to the time when the search was performed, with the last update in November 2022. After all stages of the review, 16 articles remained for complete analysis. Studies were excluded after the full-text screening for the following reasons: protocols ; compariThe included studies reported a total of 401 Achilles tendons in 371 patients; two studies included individuals with bilateral and unilateral AT , 50. CliThe samples per study group ranged from 13 to 25 participants, with a mean of 18.5 individuals in each group.All studies were clinical trials. Six studies included two intervention groups: one was eccentric exercise (EE), compared to another exercise modality, such as concentric exercise ; light tFive of the eight studies used the VISA-A scale to assess pain and symptoms , 53–55, Figures Regarding allocation of participants, 50% of the studies presented “some concerns” or “high risk” as they did not report details about how randomization and/or allocation to the various groups were performed , 53, 55.No studies reported blinding of the participants, health care professionals who administered the treatment, and evaluators, presenting a low-risk score. One study did not present information about participants and health care professionals who administered the treatment ; the patAll the articles presented the missing data reporting the reasons of exit from the study or exclusion from the intervention, being judged with low risk of bias.Seven of the eight studies presented evaluation of appropriate results, with “low risk”. Only one study presented “some concerns”  for non-Only two articles did not provide evidence of previous protocols published in study databases , 52, andRegarding the final score of risk of bias assessment, 62.5% of the studies presented “some concerns”, and 37.5% presented “high risk” of bias.2 value of 91%, showing heterogeneity between the studies. A meta-analysis with I2 higher than 75% should use the Random Effect Model. The Mean Difference (MD) found in the treatment effect was − 1.21 (− 2.72 to − 0.30), with 95% confidence interval, with a significant positive effect for the treatment of pain in Achilles tendinopathy with eccentric exercise, with the result in favour of EE compared to CG or other exercises in pain improvement.Only a meta-analysis with pain data was performed including a total of five studies. All of them used VAS/NVS to measure pain, and compared the EE with another conservative treatment Fig. . The anaThe present systematic review and meta-analysis investigated the efficacy of EE in improving pain and function in adult patients with mid-portion Achilles tendinopathy compared to other forms of exercises. The present systematic review and meta-analysis showed that EE is effective in improving disability and pain in AT patients. In the eight studies evaluating the effect of pain and disability of EE with another type of exercise, four presented favourable EE results for pain , 51, 52,The Victorian Institute of Sport Assessment-Achilles questionnaire (VISA-A) was the most commonly used outcome instrument (used in five of eight investigations) in the studies assessing disability. This questionnaire is used as an outcome measure in both research studies and in the clinical setting, and it evaluates function, activity limitation or participation restriction, in addition to documenting pain and stiffness . Two stuEEs improve muscle function, possibly through their favourable effects on neural impulse and other health-related factors, and do not produce clinically relevant adverse effects –62. EE mEccentric exercises have been tested against concentric exercise; rest/wait-and-see; light training; heavy slow resistance; or another eccentric exercise protocol. There is a wide variation between the trials regarding interventions, methods, times of evaluation of the results, and selection of the reported results.One study investigated EE and concentric exercise. This study  found imTwo studies compared EE with rest/wait-and-see. Rompe et al.  verifiedAs in several studies with active versus rest/wait-and-see treatment, individuals receiving active treatment may have higher expectations about the effects of treatment, and testing different intensity exercises against a rest/wait- and-see can lead to bias in the conclusions , 66.Silbernagel et al.  comparedThree studies compared EE with EE. The first  applied The third study applied only the Alfredson protocol . One groThis systematic review and meta-analysis focused only on studies comparing EE with another type of exercise or control group (rest/wait-and-see). One of the most interesting findings lies on the favourable results produced by this type of exercise, suggesting that EE should be an integral component of AT management. Also, the rest/wait-and-see approaches do not provide any significant benefits when compared to EE. In addition, controlled tendon loading can continue during the intervention, though further studies are needed to determine which activities are beneficial, and their frequency and intensity are recommended.The present review has identified several characteristics that should be adopted for future clinical trials. With "some concerns" and "high risk" through the risk of bias, new randomized clinical trials should be performed and adhere to the recommendations of CONSORT . In addiWe are aware of the limitation of the present investigation. Only one meta-analysis was performed, namely on pain, since it was not possible to group more than two studies for disability analysis. It is necessary to collate a larger number of studies to achieve greater statistical power . In addiThe available evidence supports the use of EE in the management of AT. Continuous load on the Achilles tendon does not adversely affect the results of pain and function, suggesting the possibility of practising some physical activities during the intervention. Some authors report that EE and HSR produce similar results, but more studies are needed to confirm this. Also, the rest/wait-and-see approaches probably do not play a role in the management of AT.


This research work showed that level and exposure to peer pressure among first-year university students having the experience of premarital sex have below-average levels of self-esteem  and have been exposed to a higher level of peer pressure . The study suggests that male first-year students with the experience of premarital sex have a higher level of self-esteem and exposure to peer pressure than their female counterparts. Self-esteem negatively predicted attitude toward premarital sex. Therefore, the researcher recommended delivering effective counseling and gender-based guidance, and life skill training for fresh students in the university.Adolescence is s period of storm and stress mainly caused by dramatic social, emotional, biological, and psychological changes. Unless supported and guided by parents, teachers, peers, and other stakeholders, they may be exposed to a variety of risky sexual behaviors. In the study area, there is no research work showing the influences of peers, self-esteem, and demographic factors on the premarital sexual practice among students. Ideas and knowledge gained in this area will enable the delivery of effective health and psychosocial intervention strategies. Thus, the objectives of this research were to assess self-esteem, peer pressure, and demographic predictors of attitude toward premarital sex among Woldia University first-year students. Correlational design was used and 343 students were selected as samples by a simple random sampling method. Relevant information was gathered using a questionnaire. The data were quantitatively analyzed using logistic regression, one sample, and an independent sample  The age of adolescence is a move from late childhood to early adulthood, characterized by rapid bodily, psychological, emotional, and biological changes. Even if they have matured sexual organs, their mood and personality swings. This fluctuation of mood and personality can affect their social relationship and their attempt to identity formation. Thus, adolescents should perform adult-like activity carefully in order to develop their identity . More thThe prevalence of the premarital sex in both developed and developing countries is high and our country was a victim of such practice . Today, Most of the students at the age of late adolescents did not agree with indulging in premarital sex. Mass media were the main sources of sexual information for men and women learned through school or peer groups. Emotional factors such as self-confidence, love, trust, fear, conformity, self-esteem, and jealousy cause premarital sex among adolescents. Lack of parental support and supervision, contraception, more women in the workforce, and use the decline of marriage are also other reasons for the commitment to premarital sex .The engagement in premarital sexual exercises extended the self-perceived worth oneself. Self-esteem gets to be higher when abstaining from sexual intercut some time recently conjugal . There iPeers are a group of individuals in the same developmental period, and with communal behaviors and emotions, who can demonstrate faithfulness and a feeling of fitting into the group. In adolescence, peers are the young people who spend time with and interact with them. In this stage, adolescents devote more of their time and communicate in a better way with their peers than in other stages of development . Peers’ Undesirable peer pressure is stronger for women than men about sexual behavior. Peer pressure may be both expressed and indirect. In expressing peer pressure, an individual is confronted openly to conform to the prevailing values, norms, and cultures in general. Research findings indicated that both peers are tending to take risks they do not want to take because they believe that this risky behavior will increase their standing and relation in the eyes of their peers and guarantee their acceptance in their group .Peer pressure substitutes the impact on adults and became the source of information, values, and behavioral influences for adolescents over the last 50 years . Today, Researchers showed that men are more likely to start sexual intercut and have more tolerance to recognize approximately sex than women . Male anvis-à-vis becoming sexually active or becoming abstinent. Adolescents in junior and senior schools display a positive attitude toward premarital sex as the majority of them do not see that going without sex would make them wiped out or see odd in society, not one or the other would it deliver them issues amid intercut when they at long last marry  respondents who had male or youthful female companions; around 129 (42.7%) have had premarital sexual interdenominational. Out of sexually energetic respondents, 85 (66.4%) had one sexual accessory, and 44 (33.6%) had two or more sexual accessories. The typical age for starting sexual intercourse was 18.4 ± 2.14 years .Different studies suggested that demographic factors such as sex, age, educational background, drinking alcohol, substance use, and lack of parental support and supervision were linked with premarital sexual activity . Even th1. What is the level of self-esteem and exposure to peer pressure among students who have experience of premarital sex?2. Are there sex differences in the level of self-esteem and exposure to peer pressure among students having an experience premarital sex?3. To what extent do sex, self-esteem, and peer pressure variables predict attitude toward premarital sex?The correlational research design was employed to investigate this study. The target populations of this study were all first-year students of Woldia University, and there are 2,424 first-year students exist among those 178 males and 165 female students. A total of 343 students were selected as a sample of this study by using simple random sampling techniques. The researcher takes the sample only from first-year students purposively because; during the study, they were only admitted to attend their class because of COVID-19 protocol. The participants of this research were determined by using n = is the sample size, N = is the total population, 1 = is constant and e is the compromise margin of error, .where; So, the sample size of this study was 343 students.A questionnaire was used to collect information regarding attitudes toward peer pressure, self-esteem, and demographic characteristics of the participants toward the premarital sexual practice of university students. The questionnaires and aim of the study were limited and prepared to measure demographic variables (sex and age) and psychosocial factors of self-esteem and peer pressure. In total, 80 students were selected and a pilot test was conducted among the students of the Debre Tabor University.Perception of Peer Pressure Scale developed by On the contrary, the self-esteem measuring scale developed by On the contrary, the sexual attitude inventory scale which was developed by First, a cooperation letter was taken from the college and submitted to the concerned body. Detail orientations about the objectives of the study were given to participants of the study and assistant data collectors. Participants were also told that the info they provide will be kept confidential and the right of withdrawal. After the researcher gained written consent from participants, data were gathered in the face-to-face fashion. In total, four competent assistant data collectors were employed to gather relevant data from participants.t-tests, and binary logistic regression were used to investigate numerical data. On the contrary, phrases, words, and sentences were employed to examine qualitative data. Tables were used to present the data. The collected data were analyzed by using SPSS version 20.All the procedures of the research were supervised by the research and community service coordinating office of the faculty. Subsequently, the collected data were analyzed by using mixed methods of analysis, i.e., quantitative and qualitative methods. Percentage, independent sample In total 178 (51.89%) of the respondents were men and the remaining 165 (48.11%) were women. The majority of the participants were aged 18–20°years, and all the respondents were never married in their lifetime and the majority of them have one sexual partner and friend .t = −40.93, p = 0.000) and have been exposed to a higher level of peer pressure   .t = 3.97, p = 0.000. In a similar manner, significant difference in exposure to peer pressure between men  and women , t = 5.82, p = 0.000. This shows that male students in the first year with the experience of premarital sex have a higher level of self-esteem and exposure to peer pressure than their women counterpart  and women , nterpart .2  = 8.836, p = 0.03. This model elucidated that only 3.2% (Cox & Snell R2) and 4.7% (Nagelkerke R2) of the variance in attitude toward premarital sex. The model also classified 78.7% of the cases correctly.The full model containing the three predictors  was not statistically significant χIt further shows that only self-esteem emerged as a unique significant contributor to the model with an odds ratio of 0.878. This suggests for every unit of growth in self-esteem respondents are 0.63 times less likely to have a favorable attitude toward premarital sex. This shows self-esteem negatively predicts attitude toward premarital sex .The study indicates that students having the experience of premarital sex have below-average levels of self-esteem. This result was related to In a similar manner, this discovery additionally supports these previous research . The patients/participants provided their written informed consent to participate in this study.The author confirms being the sole contributor of this work and has approved it for publication.