On March 11th, 2020, The World Health Organization (WHO) declared that the COVID-19 is a pandemic due to its worldwide spread. The COVID-19 pandemic has extended its impact to Saudi Arabia. By mid-February 2021, The Kingdom of Saudi Arabia has reported more than 373,000 COVID-19 cases impacting different population categories . The objective of this nationwide study was to describe and explore the characteristics of hospitalized patients diagnosed with COVID-19 in Saudi Arabia.This study was an observational epidemiological study based on collected clinical data from ten health institutions across all regions in Saudi Arabia. The study was conducted during the period from March 2nd, 2020, to January 31st, 2021. The data were collected included demographics, medical information, medications, and laboratory and diagnostic. More detailed information on usually missing factors such as smoking status, comorbidities, length of hospital stay were also collected. Both descriptive and inferential analyses were conducted using the statistical analysis software “SAS®” version 9.4.During the study period, 5286 patients were included in this study. Of these, (79.15%) were male. Of all 5286 patients, quite a high number of the studied population 2010 (38.02%) were smokers. The majority of the patients 3436 (65%) were reported to have comorbidities, with hypertension being the most common disease 1725 (32.6%), followed by diabetes 1641(31.04%). A high proportion of the patients, 2220 patients (41.99%), were admitted to the intensive care unit; of these, (33.52%) were on mechanical ventilation. Most patients received anticoagulant prophylaxis medications . All patients were given more than one antibiotic prophylaxis. Overall, the median hospital stay was 5.5 days, and the median length in the intensive care unit was 4.26 days. Around (89.14%) of patients were discharged from the hospital, and (10.8%) died.In this real-world study utilizing a large sample size, this study provides confirmatory results on the COVID-19 patients characteristics that are similar to other populations. Healthcare professionals need to give COVID-19 patients with specific characteristics including smoking, diabetes mellitus and cardiac disease more care to avoid losing these patients. Later, The Chinese healthcare authorities reported the first known case of Covid 19 in December 2019 , Jun 20.COVID-19 pandemic adversely affects the economies and millions of people worldwide. Consequently, it caused a significant burden and challenged health care systems in many countries to develop optimal guidelines for surveillance, prevention, and management of the disease. In Saudi Arabia, the first confirmed case was reported on March 2nd, 2020 Arab . The marAccording to literature evaluation, assessment of patients' characteristics has not been evaluated on a large sample size yet. Therefore, this study is important to provide comprehensive data that address the possible variations in patients' characteristics, assess the utilization of the different medications used, optimize treatment based on patient's characteristic, and manage similar pandemic in the future. Therefore, the study aimed to characterize the hospitalized patients with COVID-19 in Saudi Arabia using a large sample size.22.1The study was a retrospective, observational epidemiological study using collected data for hospitalized patients with COVID-19 from ten institutions in eight different regions (out of 13 regions) in Saudi Arabia.The study period was between March 2nd, 2020, and ended on January 30th, 2021. Routine care data from included patients were extracted from the patients' medical records, manual records and entered anonymously into a web-based electronic form (Google form). The patient data collected the following variables: patient's demographic , admission date, discharge date, and smoking status). Additionally, medical information  was collected. Furthermore, use of supporting care devices , medications including , Angiotensin Converting Enzyme Inhibitors (ACEIs), and other prescribed medications) were also collected. Patients with COVID-19 were defined if they had a confirmed positive polymerase chain reaction (PCR).We compared patients who died due to COVID-19 during admission and those who were discharged from the hospital  to assess the predictors for the outcomes.2.2U test for continuous data. Utilizing univariable logistic regression analysis, we only included the predictors (variables) that were statically significant associated with the outcome (death) in our final model. Logistic regression was used to compute the odds ratios (ORs) and 95% confidence intervals (CIs) to evaluate the associations between the potential predictors with the outcome.Demographic and clinical characteristics for our study's population were analyzed using chi-square or Fisher's exact tests for categorical data and Mann-Whitney The data included age , sex, smoking status. We also considered the following comorbidities: diagnosed hypertension, diabetes, cancer, kidney disease, liver disease, heart disease, epilepsy, autoimmune disease (rheumatoid arthritis/lupus/psoriasis), and chronic respiratory diseases including asthma and COPD. For all analyses, a 2-tailed test with a p-value < 0.05 was considered statistically significant. We calculated variables as percentages from the total population. While we calculated the length of hospital and Intensive Care Unit (ICU) stay among discharged and dead patients by dividing in total discharge and total death. Also, we calculated the ICU length of stay and use of the ventilation and general characteristics of this patient's odds of mechanical ventilation by dividing the number of patients for each period by the total number who used the mechanical ventilation.The data were managed and analyzed using Statistical Analysis of software (SAS®) . We excluded people with missing age, sex outcomes since these are likely to indicate poor data quality.3In total, 5286 adult patients admitted with COVID-19 were identified. We analyzed the distribution of COVID-19 patients admitted to hospital, discharged, reported dead, and those admitted to ICU across all regions in Saudi Arabia. Eastern region has the highest rate of admitted COVID-19 patients , followed by, Asir region , Makkah region  and Riyadh region , respectively, As for the discharged patients, the highest discharge rate was in the Eastern region , followed by Asir region  and Makkah region , respectively. Out of 574 patients who died, the Makkah region had the highest death rate, , followed Eastern region , and Madinah region , respectively, Table 1The majority of the studied population was male gender , and the mean age was 54. As age groups, the majority of the study population age group was 45–65 , followed by more than 65 years . Four thousand seven hundred and twelve patients  were discharged from the hospital, while quite a high number of the patients  died in the hospital. A high proportion of the patients, 2220 patients (41.99%), were admitted to the intensive care unit. The median of hospital stays [IQR] was (5.5) days with mean [SD] was 9.18 days, While the median of intensive care stay was (4.26) days with mean [SD] was 7.94 days. High number of patients have comorbidities , with hypertension being the most common disease , followed by diabetes . and coronary heart diseases . On the other hand, only  of the patients were obese, The highest mortality rate was  among males compared to  among females. Furthermore, recovery was higher among the 45–65 age group , followed by the 30–45 age group  from the total population (n = 5286).Two thousand and ten patients were smokers, which represent (38%) of the studied population, All patients were given more than one antibiotic prophylaxis, and Ceftriaxone was the most prescribed antibiotic with , followed by Azithromycin with  then Piperacillin/tazobactam, and Meropenem. Moreover,  were given antifungals. Overall,  of the patients had a duration of stay of seven days, and  of them had a duration of more than one to two weeks, with a discharge rate of  and , respectively.  of the patients had a duration of stay in ICU less than seven days with a discharge rate of 18.7%. The highest age group admitted to hospital was ≥ 45–<65 years ,  of these patients had a length of stay ranging from 1 to 7 days. The logistic regression analyses found that patients with heart diseases (Odds Ratios (OR) = 3.297, 95% confidence intervals (CIs = 1.976–5.501)) hypertension , patients with diabetes , smoker patients  COVID-19, patients staying the hospital for more than 14 days , patients staying the ICU for 1–7 days and more than 7 to 14 days  and , respectively, were predictors of mortality in patients with COVID-19. Male gender and old age group were also associated with mortality in patients with COVID-19, however, the association was not statistically significant. 4We have investigated the COVID-19 patients characteristics from a considerably large size data including over five thousand patients from ten institutions in nine different regions (out of 13 regions) in Saudi Arabia. The study period covered the duration between March 2nd, 2020, and January 30th, 2021.Our study finds the mortality rate of 10.85 % is lowest than globally due to several reasons may be due to increased bed capacity in the Intensive care unit (ICU) by 164%, early outpatient intervention through the creation of “fever clinics” in primary healthcare centers in all regions, and provide protocols for COVID-19 that were continuously updated by the ministry of health .We find the highest number of reported death cases in the Makkah region followed by the eastern region then Madinah region was similar to Alissa et al. study that reported the highest number of death cases in the most populated provinces in Riyadh, Jeddah, Makkah, Madinah, and the Eastern province .Smoking history contributes significantly to increase COVID 19 mortality and morbidity, almost half of the death cases in this study were smokers (49.30%). This result is constant with a previous review that shows a higher morbidity risk among smokers and ex-smokers (22% and 46%) . Even thThe present study analyzed the characteristics of patients with confirmed COVID-19 infections and found that the mortality rate was (85.88 %) among men. Our study confirms the finding of other studies; a study conducted in Peru showed that men had a higher risk of COVID-19 death than women. High incidence rates, mortality, and fatality increased with age and were higher in men 60 years of age or older . A studymeta-analysis includes 59 studies, and more than 36,000 patients found that patients aged 70 years and older have a higher infection risk, a higher risk for severe COVID-19 disease, a higher need for intensive care, and a higher risk of death once infected compared with patients younger than 70 years  to nearly two months . AccordiIn a study conducted in the US with analyzed data from 2491 adults hospitalized with laboratory-confirmed COVID-19, they found a strong direct proportion between age increasing and ICU admission rate; therefore, they consider that a risk factor for ICU admission. In this study, we found that the admission rate to the ICU increased in older age groups more than 45 years compared to those younger (18–45) .There is a wide variation in the need for invasive mechanical ventilation in ICU patients among different studies. Moreover, it is associated with a high mortality rate ranging from 16% to 78% . We findApproximately 10%–25% of hospitalized patients may develop coagulation dysfunction . TherefoIts predictable effect and convenient use may explain the increased use of LMWH compared to unfractionated heparin (UFH). Also, concerning its route of administration, it is more convenient for bedridden patients with severe symptoms than oral anticoagulants . In our meta-analysis showed contrary results representing a nonsignificant association of IVIG with lower mortality  patients out of a total of  patients showed that the prevalence of antibiotics prescribing was (74.6%). At the same time, estimated bacterial coinfection was (8.6%) from (31) studies  was the most antibiotics consuming in COVID-19 patients, followed by azithromycin. Despite the studies that reported a low rate of bacterial/fungal coinfection in patients presenting with COVID-19; however, the consumption of broad-spectrum antibiotics was widely reported, especially in ICU patients . A recen studies .In addition, a previous narrative review study found that the Azithromycin is the most frequently used antibiotic , while iThis study finds the use of ACE or ARB not associated with increased risk of COVID-19 hospitalization or subsequent complications or death, similar to the finding of multinational open science cohort study was conducted in the US and Spain; and this study included more than one million patients .5To the best of our knowledge, this is the first epidemiological and clinical characteristics analysis study at the national level representing eight regions in Saudi Arabia with 5286 patients. Furthermore, it provides information on both diseases, hospital stays and therapeutic utilization in patients with COVID-19. However, the study is limited by that; Some patients' profiles are not completed that lead to exclude these patients which might affect our results. Also, there is no information on the exact cause of death.6This largest real-world study investigated COVID-19 patient's characteristics in Saudi Arabia. It provided insights on different important patient's information including demographic, medical and medications information. Health institutions might benefit from the study results and keep more attention and consideration for smoker patients, patients with heart diseases, patients with diabetes mellitus and patients with hypertension since these patients have the highest risk to die if they have COVID-19 or to follow up with these patients to monitor COVID-19 complications and try to mitigate themThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.


Exploratory Factor Analysis (EFA) measures the underlying relationships between questionnaire items and the factors (“constructs”) measured by a questionnaire. The Home and Family Work Roles Questionnaire has not been assessed using EFA; therefore, our objective was to identify the factors measured by this questionnaire.We recruited 314 persons to complete the questionnaire and to answer several demographic questions. We determined if the data was factorable by performing Bartlett’s test of sphericity and the Kaiser–Meyer–Olkin measure of sampling adequacy. We used the Factor package in Jamovi statistical software to perform EFA. We employed an Oblimin rotation and a Principal Axis extraction method. We also calculated the internal consistency of the questionnaire as a whole as well as each individual question.Our sample consisted of 265 (85%) women, 45 (14%) men, and 3 (1%) non-binary or other genders. The mean age of our participants was 34.65  years. EFA suggested a three-factor model. Questions 11, 13, 14, 15, and 16 measured one factor (we interpreted this as “Caregiving Roles”), questions 1, 3, 4, 8, 9, 10, 18, and 19 measured a different factor , and questions 2, 5, 6, and 12 measured the “Traditionally Masculine Roles”. The questionnaire and each individual question demonstrated excellent internal consistency (Cronbach's α > 0.90).The Home and Family Work Roles Questionnaire may measure three distinct factors, which we have named Caregiving, Traditionally Feminine, and Traditionally Masculine Roles. This aligns with the theory used in developing the questionnaire. Separation of the Home and Family Work Roles Questionnaire into three sub-scales with distinct scores is recommended to measure each of the recommended constructs.The online version contains supplementary material available at 10.1186/s12905-023-02199-1. The changing role of women across the globe has been observed in many countries in the last century, as women are taking up more prominent roles and responsibilities in the government, politics, and all levels of the society –4. HistoThe Home and Family Work Roles Questionnaire was developed by Dr. Joy MacDermid in 2018 . This quTwo scoring methods were originally proposed for this questionnaire, which were item scoring (where scores range from zero to ten for each question) and percentage scoring (where the scores range from zero to 100% for each question) . The iteThe data from the Home and Family Work Roles Questionnaire can serve multiple purposes , 9. FirsExploratory Factor Analysis (EFA) is founded on philosophical and statistical principles and was fThe Home and Family Work Roles Questionnaire had not been subjected to EFA; hence its construct validity has not been previously established. It is important to establish the underlying factors within this questionnaire to measure different constructs as intended by this questionnaire. Therefore, the primary objective of this study was to undertake EFA to identify the factors measured by the Home and Family Work Roles Questionnaire. The secondary objective was to assess the internal consistency of the items in this questionnaire.This was a cross-sectional observational study to quantitatively assess the factors measured by the Home and Family Work Roles Questionnaire. Western University’s Health Sciences Research Ethics Board (HSREB) approved this study on June 25, 2020, with project ID number 115790. All study participants provided informed consent prior to participation.Study participants were selected from a larger sample of data collected through a survey designed to assess changes in mental health in terms of family responsibilities, depression, and substance use following the start of the COVID-19 pandemic . For thiGiven our purpose to validate the Home and Family Work Roles Questionnaire, this questionnaire was the main measure of our study. The instruction was: “Think about the work you did to take care of your home and family AFTER the COVID-19 pandemic . Please do not count the work done by anyone else . Slide the scale to represent the percentage of the work you did. If the question does not apply to you (for example: you do not have children), then choose not applicable.” The questionnaire consisted of 19 questions, which asked about house cleaning, indoor cleaning, laundry, home decorating, home repairs, lawn mowing, gardening, preparing meals, grocery and supplies shopping, driving family to appointments and activities, arranging family appointments and activities, maintaining vehicles, helping or supervising children with homework, caring for children in the home or when sick, caring for other family members, earning family income, managing family finances and bills. The response options were in percentages, starting from 0% (with 10% increments) and ending with 100%.To assess participants’ demographics, we assessed multiple descriptive measures. (A) Current employment status, with the response options being paid employees, self-employed, laid off, stay-at-home parent/caretaker, student, retired, unable to work due to a disability, and other. (B) Paid job status prior to the pandemic, with four response options: yes, full-time (more than 20 h/week), yes, part-time (20 or fewer hours/week), no, and other. (C) Paid job status since the pandemic started, with the same response options as the previous question. (D) Working from home as a result of the pandemic, with the response options being with a similar workload, with a greater workload, with a lighter workload, I still go into my workplace, I lost my job, and I have always worked from home. (E) Marital status, with response options of single, common-law, married, divorced, widowed, and other. (F) Gender of the participant and their partner, with response options of man, woman, non-binary, agender, and other. (G) Age, measured on a continuous scale. (H) Sex of the participant, with response options of male, female, and other. (I) The number of people in the household. (J) Ethnic origin, with response options being North American aboriginal, Black, White, Arab, Latin, Central, and South American, South Asian , West Asian , Southeast Asian , East Asian , Pacific Islands , and other.We performed all the statistical analyses using Jamovi Statistical Software Version 1.6.23.0 . We usedBefore submitting the data for EFA, we checked the EFA assumptions to ensure that the correlation matrix was factorable. Firstly, Bartlett’s test of sphericity  was usedFactor package [Principal Axis extraction method as it is the most appropriate method to recover the relatively weak factors when the assumptions of normality are violated [After establishing the assumptions of EFA, three- and two-factor solutions were sequentially examined for their adequacy. The EFA was conducted with Jamovi statistical software and its  package . We empl package . We extrviolated .Several studies recommend using a combination of different criteria, as well as the theory, to decide on the number of factors to retain in the model , 20. In Eigenvalue method. This is the most common approach to determining the number of factors to retain in the model. We followed the recommendation by Kaiser [y Kaiser  to retaiVisual scree plot. This is a graphical method consisting of the eigenvalues and the factors [ factors . We reta factors , 22.Parallel analysis. This statistical method generates a random set of data, simulating the same number of variables and participants as the real data [eal data .In addition to these statistical methods, we also considered the underlying theory in developing the Home and Family Work Roles Questionnaire. Based on the theory, three original subsets of questions (or factors) exist in this questionnaire, which are related to masculine, feminine, and caregiving roles.We established a priori criteria for determining factors’ adequacy. According to our sample size, a factor loading of at least 0.37 was considered both practically and statistically salient . Furtherp-value, degrees of freedom, mean difference, standard error difference, 90% confidence intervals, and effect size.We ran independent samples t-test to compare the means of each question for women and men. For these analyses, we had to remove three participants who had identified their gender as non-binary or other because the number of respondents did not reach the minimum power required to perform an analysis. For each of the t-tests, one of the questions was the dependent variable, and gender (at two levels: woman and man) was the grouping variable. We reported t-test statistics, We examined both the scale reliability statistics and the item reliability statistics and reported Cronbach's α. We followed the recommendations of Nunnally, where Cronbach's α of above 0.70 is considered acceptable for research purposes, and scores above 0.90 are considered excellent internal consistency .We included participants who responded to at least 16 questions (out of 19) of the Home and Family Work Roles Questionnaire on the online survey. Any participant with less than 16 responses was case-wise deleted. Our sample size was adequate for EFA for two reasons. Firstly, based on the rule of thumb method for sample size calculation, a ratio of 10 participants per question (10:1) is recommended , which iAfter removing participants who had more than three unanswered questions on the Home and Family Work Roles Questionnaire, we included 314 participants for the EFA analysis. Our sample consisted of 265 (85%) women, 45 (14%) men, and three (1%) non-binary or other genders. Further, there were 266 (86%) females, 43 (14%) males, and two (1%) participants identified as other sex. The gender of the partner was missing for 126 participants, and of those who responded, 156 (83%) had men partners, 31 (16%) had women partners, and one (1%) participant had a partner with non-binary gender.The mean age of our participants was 34.6  years. Regarding marital status, 171 (54%) were married, 98 (31%) were single, 20 (6%) were divorced, 18 (6%) were in a common-law relationship, and six (3%) were in other types of relationships. For the number of people in the household, 131 (42%) participants reported four people, 72 (23%) reported three people, 62 (20%) participants reported five people, 33 participants reported more than five people, and 15 (4%) reported less than three people live in their household.Regarding the ethnicity of the participants, the majority identified themselves as White . Of the remaining participants, 15 (5%) were South Asian , 15 (5%) were East Asian , 12 (4%) were West Asian , seven (2%) were Black, and the remaining 39 (12%) had other ethnicities such as Latino and Aboriginal.In terms of their current employment status, 152 (48%) were paid employees, 71 (23%) were students, 29 (9%) were stay-at-home parents/caretakers, 21 (7%) had other current employment statuses, 20 (6%) were self-employed, 14 (4%) were laid off, five (2%) were unable to work due to disability, and two (1%) were retired.As for their paid-job status pre-COVID-19 pandemic, 156 (50%) were working full-time, 75 (24%) did not have a paid job, 67 (21%) were working part-time, and 15 (5%) responded to other paid-job statuses pre-pandemic. Post-COVID-19 pandemic, the number of people who worked full-time had decreased to 129 (43%), the number of unemployed participants surged to 90 (30%), 56 (19%) were working part-time, and 27 (9%) responded to other. Lastly, for the question on working from home, 67 (36%) said they still go into their workplace, 56 (30%) were working from home with a similar workload, 34 (18%) with a greater workload, 11 (6%) with a lighter workload, 14 (8%) were always working from home, and three participants (2%) had lost their job.2(171) = 2120.19, p < 0.001. Further, the Kaiser–Meyer–Olkin measure of sampling adequacy was 0.90, which is well above the minimum sampling adequacy requirements for conducting EFA.The results of Bartlett’s test of sphericity indicated that the correlation matrix was not random, χParallel analysis, eigenvalue method, and scree plot Fig.  suggeste r = 0.71, which is consistent with the expectation that caregiving is a more traditionally feminine role. The remaining two correlations were below 0.70; therefore, one can conclude that the three factors were distinct from each other.All three factors had at least three salient loadings at values of 0.40 or greater. Considering the conceptual commonalities between the reasons (variables), we labelled factor one as Caregiving Roles, factor two as Traditionally Feminine Roles, and factor three as Traditionally Masculine Roles. The correlation of the factors was checked and established well below the threshold for high correlation. The highest observed correlation was between Caregiving and Feminine roles, with1- Caregiving roles. Questions 11, 13, 14, 15, and 16 were labelled as the caregiving roles. These questions related to arranging family appointments and activities, helping or supervising children with homework, care for children in the home or when sick. Additional file 2- Traditionally feminine roles. Questions 1, 3, 4, 8, 9, 10, 18, and 19 were all referring to feminine work roles and responsibilities. These questions asked about house indoor cleaning, laundry, home decorating, preparing meals, shopping for groceries and supplies, driving family to appointments and activities, earning family income, and managing family finances or bills.Question 17  had almost equal loading  on both the Caregiving and Traditionally Feminine Roles factors, 0.32 and 0.35, respectively. Hence, it was not categorized as either of these factors. Please refer to Additional file 3- Traditionally masculine roles. Lastly, the third factor was labelled as Traditionally Masculine Roles and entailed questions 2, 5, 6, 7, and 12. These questions relate to outdoor cleaning, home repairs, lawn mowing, gardening, and maintaining vehicles. Descriptive statistics can be found in Additional file The results indicated that, except for questions 18 and 19 (earning family income and managing family finances/bills), there was a statically significant difference between men and women for all the remaining questions. For questions related to outdoor cleaning, home repairs, lawn mowing, and maintaining vehicles , men had done a greater percentage of the family work  compared to women. For all the remaining questions , women had done more work  than men. The detail of these analyses can be found in Table These were based on independent samples t-test for each question to compare the mean score differences between men and women. The underlying assumptions for normality and homogeneity of variance were violated for some of the questions. However, we decided to employ this test because most items were supported (could put the number supported here too) and since this test has a high tolerance for non-normality in samples higher than 25 in each group.The overall Cronbach’s α of the questionnaire was 0.94, indicating excellent internal consistency. When items were dropped one at a time, the overall Cronbach’s α remained at 0.93 to 0.94; hence, no item reduction was required.We conducted an EFA to determine the construct validity of the Home and Family Work Roles Questionnaire and to assess the number of latent factors it entails. Our research identified that this questionnaire appears to measure three distinct factors: Caregiving Roles, Traditionally Feminine Roles, and Traditionally Masculine Roles. Our results align with the theoretical objectives in the designing and development of this questionnaire, which suggested the existence of three subsets of factors. These results are the first to explore the validity of using the Home and Family Work Roles Questionnaire as a self-reported assessment of family work roles and responsibilities among a large sample of 314 participants. Family work role, in contrast to employment status, is unpaid work that is often not measured or considered in health research.The results of the EFA indicated strong support for a three-factor solution comprising Caregiving Roles, Traditionally Feminine Roles, and Traditionally Masculine Roles. Further, by using a conservative correlation threshold of 0.37 to determine factor loading, we categorized 18 questions into three latent factors without confounding or overlap. The correct number of factors to retain in the model, resulting in a model that is parsimonious yet comprehensible, is one of the most important decisions in EFA . ExtractWhen looking at the amount of work done by women and men, women outperformed men in tasks relating to housekeeping work, and caregiving to children and other family members. With respect to earning family income and managing family finances, women and men had a similar contribution. In a 2016 study  that looIn the subcategory of the questions labelled as Caregiving Role, women had done significantly more work compared with men in all tasks, and the effect sizes were large. Only one question (question 17: care for other family members) had similar cross-loading on feminine and caregiving role factors; meaning that unlike other caregiving roles that had strong loading on Caregiving Roles factor, caring for other family members could also be considered part of feminine roles and responsibilities. Upon examining the amount of work done within this task between genders, even though women had done a greater proportion  of the family work compared with men, the mean difference was not as large as other caregiving tasks and the effect size was small to medium . This suOur study categorized earning family income as a Traditional Feminine Role factor. Although men had done more work in this task compared with women, the mean difference was small, and the difference was not statistically significant. Earning family income was traditionally considered a gendered expectation for men, as more families were “head-complement” family type where women do not work outside the home . Women jInternal consistency reliability assessment suggested that all 19 questions of the Home and Family Work Roles Questionnaire measured the same construct and that there was no indication that any of the questions should be excluded. The Cronbach’s α of 0.94 indicates excellent reliability  when usiIt is difficult to draw comparisons between the Home and Family Work Roles Questionnaire and other questionnaires as no other questionnaire exists that measures the construct that this questionnaire intends to measure. For instance, the Social Roles Questionnaire is a well-developed questionnaire, it has two inherent differences with Home and Family Work Roles Questionnaire . For oneAs this study was nested within a larger cross-sectional and anonymous study, our ability to collect data for testing other psychometric properties was limited. For example, even though we reported the internal consistency, we were not able to calculate the test–retest reliability. Further, we were only able to do EFA since no prior data existed on the Home and Family Work Roles Questionnaire. Nonetheless, the EFA results reported in this study are supported by theory. Therefore, future studies are warranted to further approve the three-factor solution proposed in this study by confirmatory factor analysis and structural equation modelling. Finally, our sample had a large percent of women participants and not a sufficient number of other genders to statistically analyze the latter subgroup.The Home and Family Work Roles Questionnaire was validated using EFA, and three factors were established, which were Caregiving, Traditionally Feminine, and Traditionally Masculine Roles. Further, excellent internal consistency of the Home and Family Work Roles Questionnaire was established (Cronbach's α = 0.94). We suggest future studies to further probe the recommended factors by conducting confirmatory factor analysis and to assess other important psychometric properties such as the test–retest reliability and content validity.Additional file 1. The descriptive statistics of the Caregiving, Tarditionally Feminine, and Traditionally Masculine factors.


Background: With the growing life expectancy for older adults, this study aims to examine the correlation among sociodemographic characteristics and the combined effect of QoL-related domains including physical health, psychological health, social relationships, and environmental factors with the overall QoL level of older adults in Taiwan. Methods: The WHOQOL-BREF Taiwanese Version questionnaire was adopted and conducted using a randomized telephone interview system from community household elders. In total, 1078 participants aged 65 years and older were recruited. A multiple regression model was used to examine the statistical significance between the overall QoL score as the dependent variable and the sociodemographic characteristics, and 26 items of QoL-related questionnaires as the independent variables. Results: Categories including female, aged 85 years and above, higher education level, and better financial situation had significantly higher overall QoL level. Except the physical health domain and six items, the correlations among all other domains and their including items of questionnaires with overall QoL level were significant. Conclusion: The Taiwanese WHOQOL-BREF questionnaire can be used to examine the overall QoL level of elders in Taiwan. Nevertheless, the robust systems of universal health care and long-term care in Taiwan may have led to the no significance of the six items. The World Health Organization (WHO) predicted that between 2015 and 2050, the proportion of people aged 60 years and older will approximately double from 12% to 22% . ConsequAging is a continuous process of change in mental and physical health that generally leads to the loss of functional capabilities and ability to perform daily activities . Thus, rThe WHO defined QoL as a person’s perception of their capacity in life and the value that they bring to society ,6, alongWith regard to saving on long-term care expenditures, it is essential to support the long-term QoL of independent older adults and older adults living in care communities . PreviouOver the past two decades, individual QoL has become more valuable and appreciated in healthcare systems, particularly emphasizing physical health ,13,14, pThe impact effects of the factors reflected in the assessment scale items differ between geographical regions. This study adopted the Taiwanese version of WHOQOL-BREF, which comprises 26 items affecting QoL , and expPast studies have found that cultural variables are the most important explanatory factors for QoL in older adults. They found significant differences in QoL between older adults in developed and developing countries . A QoL sOur hypotheses are as follows:H1. Sociodemographic characteristics, including gender, age, education level, living arrangement, and financial situation, will predict overall QoL in older adults.H2. Physical health, psychological health, social relationships, and environmental factors will predict overall QoL.H3. There will be some cultural differences in the application of the WHOQOL-BREF questionnaire to the elderly in Taiwan.For this study, a randomized cross-sectional survey was conducted. Data were obtained through a computer-assisted telephone interview system  over 2 mTelephone interviews were conducted by trained hirelings of a great Taiwanese opinion polling company, all of whom were well-versed in the local language . The telephone survey used a multistage stratified random sampling technique to randomly dial telephone numbers stratified by local governments in Taiwan. Interviewers screen older adults over the age of 65 and those without cognitive impairment for telephone interviews. Of the 1339 elderly people who received a call from the survey center, 261 declined to be interviewed. Finally, a valid sample of 1078 participants was obtained, and the percentage of successful telephone interviews was 80.5%. The estimated error was approximately ±2.99% with a 95% confidence level. This study used G*Power software  to calculate sample size and power analysis. The valid sample size exceeded the requisite minimum sample size of 179, which was determined using G*Power software at α error probability = 0.05 and power (1 − β err prob) = 0.90  in this This study was approved by the Research Ethics Committee of the National Taiwan University (IRB No. 201912ES054). This study followed relevant regulations on human research to ensure that this article complies with the principles of medical ethics.(1)Sociodemographic: gender, age, education level, living arrangement, and financial situation.The questionnaire inquired into overall QoL (the dependent variable), sociodemographic characteristics, and items under the QoL domains . All responses were given on a 5-point Likert scale . An instructor reviewed the questionnaire for validity and reliability, and the questionnaire was tested and revised before it was given to the participants. The independent variables for evaluating the outcomes were as follows:The gender variable distinguishes between men and women. The age variable is divided into three categories: 65 to 74 years old, 75 to 84 years old, and 85 years old and above. Education level variables are divided into illiterate, elementary school, secondary school, senior high school, university, and master’s degree or above. Living arrangement variables are divided into living alone, living with spouse, and living with regular family members.(2)The Taiwanese version of the WHOQOL-BREF divided into four domains: physical health (7 items), psychological health (6 items), social relationships (4 items), and environmental factors (9 items).The options of the financial situation in this study were modified from the classi-fication of the Survey on the Status of the Elderly in Taiwan: well off, roughly enough, slightly difficult, and quite difficult. This study combined “slightly difficult” and “quite difficult” into the “financially struggling” options .(2)The TIn this study, a confirmatory factor analysis was used for evaluating all items and for confirming the reliability and validity of the four domains. The model fit index was used to confirm the model fit and overall construct validity. Confirmatory factor analysis provides many reliability and validity indicators and is widely used in testing measurement scales.With regard to absolute model fit, the chi-squared value of the conceptual model was 396, and the degrees of freedom was 293. The model GFI (goodness-of-fit index) was 0.99, which was greater than the requisite minimum of 0.90. The SRMR  was 0.04, which was lower than the requisite maximum of 0.05. About comparative model fit, NNFI (non-normed fit index) = 0.99, NFI (normed fit index) = 0.98, CFI (comparative fit index) = 0.99, and IFI  = 0.99, all of which were greater than the requisite minimum of 0.90. Regarding parsimonious fit, PNFI = 0.88 and PGFI (parsimony goodness-of-fit index) = 0.77, both of which were greater than the requisite minimum of 0.50. Therefore, the conceptual model had good fit and the study had good construct validity .The factor loading λ values of “dependence on medicinal substances and medical aids”, “negative feelings”, “sexual activity”, “physical environment”, “health and social care: accessibility and quality”, and “food availability” were 0.48, 0.46, 0.48, 0.47, 0.48, and 0.43, respectively, which were close to the requisite minimum of 0.5-the threshold recommended by Hair et al. ,29. The Furthermore, the latent domain of this study had good internal consistency: the CR values of this study ranged from 0.70 to 0.85, all of which were greater than the requisite minimum of 0.7 recommended by Hair et al. ,30 Tabl.We first presented the sociodemographic characteristics of the study participants. After analysis of reliability and validity, all items were consolidated for path analysis. Since all factor loading values of the 4 domains are higher than 0.4, this study summed the facets scores of all domains separately for path analysis. This article selected item 1 of the WHOQOL-BREF, “Overall, how do you evaluate your QoL ,” as a dependent variable. In this study, the tolerance value was between 0.54 and 0.98 (greater than 0.1); the variance inflation factor was between 1.02 and 1.83 (less than 10), which indicated no problems with collinearity . This paWith regard to the sociodemographic of the older adult study sample, men accounted for 39.0% of participants. The percentages of individuals with illiteracy and with elementary school, secondary school, senior high school, university, and graduate qualifications were 8.6%, 30.7%, 10.5%, 20.2%, 26.5%, and 3.4%, respectively. Regarding living arrangements, older adults living alone, living with spouse, and living with other family members accounted for 11.6%, 26.1%, and 61.8% of the sample, respectively. Regarding financial situation, the older adults who were well-off, roughly enough, and financially struggling constituted 7.1%, 79.5%, and 13.4% of the sample, respectively .For the population variables, this study transformed the nominal scale into dummy variables and added them to the regression equation. With men as the reference group, the QoL of women was relatively high. The standardized coefficient of women was 0.12, which was statistically significant .Taking 65 to 74 years as the reference group, the QoL of older adults who were 85 years and older was relatively high. The standardized coefficient for older adults 85 years and older was 0.18, which was statistically significant .In this paper, the older adults who were not literate were used as the reference group. The QoL of older adults with an education level above elementary school was higher than illiterate group. The standardized coefficients of older adults above elementary school were 0.30, 0.27, 0.39, 0.30, and 0.86, all of which were statistically significant. The QoL of older adults with a master’s degree or above was the highest .For the independent variable “living arrangement” of the elderly, the regression model used “living alone” as the reference group. All dummy variables of living arrangement did not reach the statistical significance level, indicating that the living arrangement of the elderly in Taiwan did not affect the evaluation of quality of life. According to the Survey on the Status of living alone elderly in Statistics Bulletin, there are 42,000 elderly people living alone in Taiwan. The services provided by Taiwan’s Ministry of Health and Welfare for the elderly living alone in 2020 include: home services (29.1%), catering services (35.5%), telephone greetings (19.9%), caring visits (15.3%), escorting to the hospital (0.2%) . PerhapsOlder adults who were financially well off were used as the reference group. The QoL of older adults who were roughly enough and financially struggling was poor. The standardized coefficients older adults who were roughly enough and financially struggling were −0.27 and −0.48, respectively, which was statistically significant. Therefore, the poorer the financial situation of older adults, the poorer their QoL .The standardized estimated coefficients of the four domains of physical health, psychological health, social relationships, and environmental factors were 0.04, 0.31 **, 0.11 **, and 0.16 **, respectively. Thus, the better the psychological health, social relationships, and environmental factors of older adults in Taiwan, the higher their QoL with statistical significantly. The results also indicated that psychological health and environmental factors can improve the QoL of older adults more than social relationships and physical health .After evaluating the domains, this study examined the items of overall QoL as the dependent variable. The items in the four domains of the WHOQOL-BREF were input into four regression models. In the physical health domain, the three items, “activities of daily living”, “dependence on medicinal substances and medical aids”, and “mobility”, were not significant. In the psychological health domain, “thinking, learning, memory, and concentration” was also not significant. In the social relationships domain, all items were statistically significant. In the environmental factors domain, “health and social care: accessibility and quality” and “transport” were not significant .By adopting the psychometric properties questionnaires of WHOQOL-BREF instrument to assess the QoL of elderly people in Swiss, Steinbϋchel has demonstrated that the measurement by a systemic comparison of item-level profiles in specific group would be more informative than the four domains and assessment of QoL would be, to some degree, determined by objective evaluation, such as: health care system, individual expectation level, and economic resources . This stThe results of the Sociodemographic Characteristic variables in this study indicated that the women, older-aged, more educated, and more financially well-off elder adult group were predictable having better overall QOL outcome, which was like the findings from several studies previously ,36,37,38Although, Lee’s study  has founAligning with the findings from Gobbens in Belgium , Jeste dReviewing the studies conducted by Gobbens and Momenabadi ,44, whicLiu and Zhou observed a higher overall QoL among older adults in rural China, which may be because they can get care supporting by their children living together in the family ,35. We sJeste’s study has demonstrated that the self-rated successful aging was associated with better interacting components including physical function, psychological traits, social engagement, and environmental status for the mass community dwelling elder people who live in San Diego, U.S.A. by telephone interview at home . MeanwhiIn recent two decades, Taiwan has made improvement in the QOL on elders by some positive factors. The first one was the “National Health Insurance System” (NHIS) initiation which has provided the effectiveness of improving access to health care and maintaining well quality for physical health care ; The secIn addition to the domains, we measured the correlation between 26 items within the four domains and the overall QoL score, there were 6 items which revealed without significant correlation to overall QoL outcome and to be exploring the causal factors as below.Jeste and Hsu and Lin have indicated that physical health conditions, such as resilience and fitness, may lead to more successful aging ,54,55. HFurthermore, a study by Chi in Taiwan has provided positive evidence supporting the effectiveness of an intervention program in improving psychological status, social participation, and active aging through the Community Health Creation Program. Such programs could aid older adults with cognitive training, emotional awareness, and coping skills during their usual daily activities . The resOur study reveals that the four domains play the relatively different important role in predicting QoL among elder adult population. Our findings should be interpreted in light of the following limitations. First, this is a cross-sectional study, illustrates that the female gender, age of 85-year-old above, and higher social hierarchy groups (both education and socioeconomic status) tend to have a better overall QoL satisfaction compared to other groups. Second, by ranking sequent, the factors including psychological health, social relationship, and environmental domains are positive correlated to overall QoL score with statistical significance; however, physical health domain factor does not demonstrate significant correlation. The third, among the four domains, there are six items which do not play the significant role in determining overall QoL of Taiwanese elderly, include: (1) activities of daily living, (2) dependence on medicinal substances and medical aids, (3) mobility, (4) thinking/learning/memory/concentration, (5) health and social: accessibility and quality, and (6) transportation. Our investigation concluded that the physical health domain and above six items were not significantly correlative to overall QoL satisfaction of Taiwanese elders due to other contribute factors such as accessible medical services, affordable health insurance system, and community long-term care support.During this study, no large-scale COVID-19 outbreak occurred in Taiwan. The effect of COVID-19 on the QoL of older adults cannot be included in this study. Future research should conduct in-depth investigations on COVID-19′s effect on the QoL of elders. This study primarily collected data through telephone interviews. The responses provided by older adults may be inaccurate due to problems with selective memory and the telescoping effect. Due to time and financial constraints, this study was unable to adopt a longitudinal research approach to accurately determine a causal relationship. Future research should adopt a longitudinal research method with sufficient funds and time. Additionally, this study collected quantitative data, and many in-depth qualitative viewpoints cannot be included. We recommend that future researchers examine both qualitative and quantitative data for more accurate and rigorous results. Finally, due to cultural differences and biases, our findings may not be generalizable for other populations.This study conducted telephone questionnaire surveys among the Taiwanese elderly population (aged 65 years and above) by using an adopted-Taiwanese version WHOQOL-BREF stool. This investigation revealed that the four domains play relatively different important roles in predicting QoL among the elder adult population. Moreover, the result of this study also illustrates that not all the items of the WHOQOL-BREF questionnaires can significantly predict QoL of elder adults, and cohort studies should be conducted to demonstrate the consistently reliable result in the future. We also strongly believe that the significant QoL correlative independent variables should be emphasized and considered to be not only applied in formulating long-term care policy by the government, but also for further relevant research purposes.


Cuscuta spp.) species are obligate parasitic flowering plants that totally depend on host plants for growth and reproduction and severely suppress hosts’ growth. As a rootless and leafless plant, excised dodder shoots exhibit rapid growth and elongation for several days to hunt for new host stems, and parasitization could be reestablished. This is one unique ability of the dodder to facilitate its success in nature. Clearly, excised dodder stems have to recycle stored nutrients to elongate as much as possible. However, the mechanism of stored nutrient recycling in the in vitro dodder shoots is still poorly understood. Here, we found that dodder is a carbohydrate-rich holoparasitic plant. During the in vitro dodder shoot development, starch was dramatically and thoroughly degraded in the dodder shoots. Sucrose derived from starch degradation in the basal stems was transported to the shoot tips, in which EMP and TCA pathways were activated to compensate for carbon demand for the following elongation according to the variations of sugar content related to the crucial gene expression, and the metabolomics analysis. Additionally, antioxidants were significantly accumulated in the shoot tips in contrast to those in the basal stems. The variations of phytohormones  indicated that they played essential roles in this process. All these data suggested that starch and sucrose degradation, EMP and TCA activation, antioxidants, and phytohormones were crucial and associated with the in vitro dodder shoot elongation.Dodder ( Cuscuta species (dodders) are holoparasitic plants that can grow on a wide range of dicot plants, such as alfalfa, tomato, and soybean , sucrose transporters (and other specific sugar receptors), and hexokinase (HXK)  . Undernuin vitro dodder growth are very limited.Due to the regulatory and signaling function, carbohydrates could significantly affect the metabolism and development by controlling the essential metabolic processes required to adapt to various stresses, such as drought, chilling, and nutrition starvation . Sugar sin vitro. Here, the temporal and spatial distribution characteristics of carbohydrates were determined in the in vitro dodder shoots, and expression profiles of carbohydrate metabolism-related genes were also detected. Meanwhile, metabolic changes of in vitro dodder shoot development were analyzed through the metabolomics data, suggesting that differential metabolites are involved in various metabolic pathways, such as carbon metabolism, secondary metabolite synthesis, oxidative stress, and hormone metabolism. Furthermore, the contents of plant hormones, including abscisic acid (ABA), jasmonic acid (JA), and indole-3-acetic acid (IAA), were first quantified during the in vitro dodder shoot growth in this study. These results would provide valuable information for preventing the in vitro dodder attack and source-sink partitioning in plants.In addition, metabolomics, as an important tool to study the metabolic pathways of the biological system, may provide a new perspective for the understanding of dodder shoot development Cuscuta suaveolens, a gift from Dr. P. Reisen, Forage Genetics International, Indiana) were treated with sulfuric acid for 30 min to break seed dormancy, and then sulfuric acid was removed by rinsing with water. Seeds were kept at 23°C for several days on wet filter paper until the seedlings were approximately 3 cm long. Dodder seedlings were placed at the base of 1-week-old alfalfa seedlings. To facilitate parasitization, dodder radicles were slightly submerged in the soil to anchor the host seedlings. A total of 10 dodder seedlings in each pot succeeded in twisting around the stems of alfalfa seedlings and developing haustoria. The day/night length was 16 h/8 h, and the temperature was maintained at 23°C (day) and 18°C (night) in the greenhouse of China Agricultural University, Beijing. After parasitization for 3 weeks, healthy dodder shoot tips (about 7 cm long) were collected and used in this study. Detached shoots were grown in a box containing a layer of wet gauze without any nutrition supplement and incubated in a growth chamber in dark at 23°C. Later on, the detached dodder shoots were harvested on different days  after incubation. The morphological basal stem (5 cm) of detached dodder shoot was divided into two segments on average, and the shoot tip  was defined as the third segment  after incubation. The content of starch was determined according to the previous method with some modifications . Concentrations of glucose, fructose, and sucrose were determined using individual standards  was used for the expression analysis of SPS. The other one was a truncated sequence. Due to lack of gene member annotation, we searched the sequence on the NCBI website, finding that it was homologous with SPS1 of other plant species, and we defined it as SPS1 in this study. Similarly, SUS2 and SUT2 were also defined by their corresponding homologs of other plant species, respectively. The gene names currently given are based on the best aligned homologous genes using the standard databases . They may change when better genome sequence information of dodder becomes available. The primers used for real-time qPCR amplification are listed in Total RNA was extracted from dodder shoots using the RNA Simple Total RNA Kit  following the instructions of the manufacturer. RNA concentration was determined by using a Nanodrop spectrophotometer . Reverse transcription was performed using a PrimeScriptTM RT reagent kit . Then, all qRT-PCRs were performed in triplicate using TB Green R Premix Ex Taq™ II  in an ABI-7500 fast Real-Time PCR Detection System. A 2is study . Three baveolens . In partg for 15 min at 4°C. The supernatant was transferred into a new tube, and the extracts were vacuum-dried. Second, the dried extracts were reconstituted with 500 μl of acetonitrile/water  by sonication on ice for 10 min. The extracts were then centrifuged at 15,000 × g at 4°C. Finally, the supernatant (about 70 μl) was filtered and transferred to a fresh 2-ml glass vial for LC/MS analysis. Meanwhile, 10 μl of every sample was prepared as a QC sample for UHPLC-QTOF-MS detection.Sample extraction was performed according to the previous study with some modifications . First, The freeze-dried extracts were used for metabolomic analyses. LC-MS/MS analyses were performed using an UHPLC equipment  with a UPLC BEH Amide column . The mobile phase consisted of 25 mmol/L ammonium acetate and 25 mmol/L ammonia hydroxide in water (pH = 9.75) (A) and acetonitrile (B). The gradient elution procedure was carried out as follows: 0 min, 95% B; 0.5 min, 95% B; 7 min, 65% B; 8 min, 40% B; 9 min, 40% B; 9.1 min, 95% B; and 12 min, 95% B. The injection volume was 2 μl (positive or negative), respectively. The triple TOF-MS (AB Sciex) was used to acquire MS/MS spectra based on an information-dependent acquisition (IDA). In this mode, the full scan survey MS data was continuously evaluated by the acquisition software , which triggered the acquisition of MS/MS spectra depending on the preset parameters. In each cycle, 12 precursor ions with an intensity above 100 were chosen for MS/MS at 30 V collision energy. The condition of the electrospray ionization (ESI) source was set as follows: ion source gas 1 as 60 psi., gas 2 as 60 psi., curtain gas as 35 psi., source temperature as 600°C, and ion spray voltage floating (ISVF) as 5,000 or 4,000 V in positive or negative modes, respectively.t-test  and the variable importance in the projection (VIP > 1) of the first principal component of the OPLS-DA model. In addition, the KEGG database was used for annotation of the pathways of differential metabolites (DMs). The DMs were used for further analysis and screening of the key pathways based on enrichment analysis and hierarchical clustering analysis.Ions with a relative standard deviation (RSD) < 20% in the QC sample analyses were used for further univariate and multivariate statistics . We perfin vitro. LC–MS/MS method with minor modification was used to quantify the phytohormones  vials and then injected into the LC/MS system.Dodder stems were harvested after growth at different times hormones . BrieflyP-value < 0.05.Statistical analysis of all data was performed using the SAS software . Significant differences between treatments were determined by one-way ANOVA followed by Fisher’s least significant difference (LSD) test with a in vitro. In contrast, the dry weight presented an upward tendency from 0 to 2 days and then decreased from 2 to 4 days in shoot tips (T)  . Meanwhier parts .in vitro dodder shoots recycled stored carbon to maintain the shoot tip development, the contents of starch and soluble sugar were analyzed in this study. During in vitro dodder shoot growth, starch content was dramatically decreased on day 1 and then reduced continuously on days 1–4, representing 28.6% and 31.1% of those on day 0 in the basal and middle stems, respectively. A similar pattern was observed in the shoot tips, however, starch content remained at a high level on day 4 in the shoot tips, more than 50% of that on day 0  irreversibly catalyze the hydrolysis of sucrose into fructose and glucose. The expression of NINVs was markedly induced in different segments and remained at a high level on day 4 after culture in vitro  analysis was employed to evaluate the performance of the UPLC-QTOF/MS. As shown, quality control (QC) samples were separated from tested samples, and the experimental samples were clearly separated into the different subgroups by PC1 and PC2 (t-test (P < 0.05) were applied to detect the differential metabolites (DMs) among subsample groups: day 0 vs. day 1, day 0 vs. day 2, and day 0 vs. day 4 , the contents of sucrose, D-fructose, and D-mannose were increased on day 1, and then slightly declined on days 2–4. In contrast, the levels of glycerol 3-phosphate, succinate, and D-ribulose 5-phosphate, which are involved in EMP, TCA, and PPP, declined until day 4, indicating that the metabolism slowed down in the in vitro shoot tips due to the limited energy supply.Additionally, carbohydrate metabolism, such as starch and sucrose metabolism, galactose metabolism, PPP pathway, and TCA cycle, were frequently presented in the enrichment analysis. Hierarchical cluster analyses of these carbohydrate metabolites presented the metabolic characteristics during the p growth . Among tin vitro dodder shoot tips development. Correspondingly, the levels of L-tryptophan, indoleacrylic acid, and indole-3-lactic acid were greatly increased compared with those on day 0, suggesting that these metabolites might play a critical role in the process of the in vitro shoot tips elongating  biosynthesis pathway, were activated during the ongating .in vitro dodder shoot development. Time-specific  DMs were analyzed between the basal stems and shoot tips. Venn diagrams analysis revealed that 165 DMs were commonly regulated between the basal stems and the shoot tips on days 0, 1, 2, and 4 . All of these antioxidants were dramatically upregulated in the shoot tips in contrast to those in the basal stems as time was prolonged in vitro (in vitro dodder shoot elongation by maintaining a robust ROS-scavenging capacity.Plant ROS plays a crucial signaling role in plant response to environmental stress, but the excess ROS could cause oxidative injury to cell components . In our oot tips . The metin vitro –7. Thesein vitro dodder shoot growth. Based on these results, we proposed that soluble sugars derived from starch degradation are transported to the shoot tips, supporting the subsequent development of the in vitro dodder shoots. Furthermore, we systematically investigated the metabolic changes during the in vitro dodder shoot growth, and large numbers of DMs were identified in this process. When the shoot tips gradually developed, starch content dramatically decreased, and the TCA, EMP, and PPP pathways related to DMs were upregulated in the shoot tips, providing energy and substances for the following growth. Meanwhile, antioxidants, such as α-naphthylamine and ascorbic acid, remained at a higher level in the shoot tips than those in the basal stems, indicating the robust ROS-scavenging capacity in the shoot tips. Additionally, we also analyzed phytohormone changes in detached dodder shoots, suggesting their possible roles in modulating the in vitro dodder shoot growth. In summary, the large amounts of carbon degradation and transportation, antioxidants in cooperation with phytohormones, contribute to the in vitro dodder shoot growth under nutrition starvation (In this study, we analyzed the changes in carbohydrate contents, as well as the gene expression patterns during the arvation . This stThe original contributions presented in the study are included in the article/YXZ and MZ designed the project and oversaw the project management. YXZ and YSZ performed the experiments. YXZ analyzed the data and wrote the draft. YXZ, LJ, ZL, and MZ revised the manuscript. All authors approved the final 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.


Lightweight aggregate concrete (LWC) and fiber reinforced polymer (FRP) reinforcement are potentially more sustainable alternatives to traditional steel-reinforced concrete structures, offering several important benefits. To further the knowledge in this area, the physical–mechanical properties of LWC produced with 0%, 50%, and 100% expanded clay aggregate were assessed. Subsequently, the flexural behavior of LWC beams reinforced with steel reinforcement and glass and basalt FRP bars was tested. The results of the experimental program allowed quantifying of the effect of expanded clay aggregate incorporation on LWC properties. The use of FRP reinforcement was also compared to steel-reinforced concrete beam behavior. The results of this study can provide additional support for the use of innovative materials such as LWA and FRP reinforcement. By replacing coarse normal weight aggregate with lightweight aggregate (LWA) such as volcanic pumice, clay, oil palm, and fly ash, lightweight aggregate concrete (LWC) is produced. The generic term LWC refers to any concrete with an oven-dry density lower than 1850 kg/m3 ,3.In terms of material, the LWA used to produce the LWC, can be either artificial aggregate, such as expanded shale and expanded clay, or natural aggregates such as scoria and pumice ,5. The uFor example, Hedjazi  studied Over the years, expanded clay—a kind of LWA—has proven to provide good performance to LWC in the long run, due to the close compatibility of stiffness between the LWA and the cement paste, which reduces micro-cracking . It is Sonia and Subashini  experimeIn addition to innovations at the level of concrete constituents, such as the use of LWA, innovations for structural, durability, and environmental beneficiation of concrete also include reinforcement. In this regard, fiber reinforced polymers (FRPs) are increasingly used as an alternative reinforcing material to steel reinforcement . FRP is Glass fiber reinforcement polymers (GFRPs) and basalt fiber reinforcement polymers (BFRPs) are commonly used and widely applied FRPs in reinforced concrete structures. The use of GFRP increases flexural stiffness, reduces deformability, and increases the resistance capacity of concrete structures. It is an anisotropic composite material with high tensile strength compared with steel bars ,24.The deflections and crack width of FRP-reinforced concrete members should be greater than those of steel-reinforced concrete members due to the lower modulus of elasticity and higher tensile strength compared with steel bars . TherefoBFRP has higher tensile strength compared to GFRP and better bonding to the concrete . The incConsidering the results from the literature presented above, a clear gap was identified in relation to the knowledge of the behavior of FRP reinforcement embedded in LWC. Specifically, the effect of LWA incorporation on mechanical properties needs to be further studied, as well as the structural behavior of FRP-reinforced LWC members. In particular, illuminating the differences between BFRP and GFRP is needed.Therefore, within this study, an experimental program was conceptualized and executed. For this purpose, the physical–mechanical properties of LWC produced with 0%, 50%, and 100% expanded clay aggregate were assessed. Subsequently, the behavior of LWC beams reinforced with steel reinforcement and GFRP and BFRP bars was tested in three-point bending. The results of the experimental program allowed quantifying of the effect of expanded clay aggregate incorporation on LWC properties.w/c ratio of 0.35 and a relatively high cement content of 500 kg/m3 were selected. The cement was Ordinary Portland Cement (OPC) CEM I 42.5 N tested per BS EN 196-2 [Cement, fine aggregate, coarse aggregate, water, and superplasticizer have been used to produce high strength SCC. Hence, a relatively low EN 196-2 ; its cheLocal natural quartz river (Danube River in Hungary) sand and two types of coarse aggregate were used: natural aggregate (NA) and expanded clay with maximum sizes of 8 mm. The choice for maximum aggregate size both for the NA and expanded clay was justified from the point of view of SCC production, which requires smaller maximum aggregate sizes. Fine and coarse aggregate were used in mass proportions of 45% and 55%, respectively.Expanded clay has been used as LWA with different proportions  of normal coarse aggregate mass. The sieve analyses for the three blends of aggregate are shown in Sand dune coated GFRP, BFRP, and steel B500B bars with diameters of 10, 14, and 8 mm, respectively, were used as tension reinforcement in the tested beams. The main properties of the used reinforcements are shown in The mixing procedure was partitioned into three stages: in the first stage the coarse and fine aggregate and cement were added and mixed; in the second stage, water was added; and finally, both BASF Glenium C300 and BASF Glenium 51 superplasticizers were added. This procedure allowed achievement of the required workability and homogeneity of the mixes. Three mixtures were produced with an increasing percentage of LWA replacing NA: LW0% is the mix with 0% of expanded clay, LW50% is the mix with 50% of expanded clay and 50% of NA, and LW100% is the mix with 100% expanded clay. All mix proportions are presented in In order to ensure proper SCC behavior, slump flow and V-funnel tests were conducted directly after mixing, according to the European guidelines for SCC, EFNARC  see Fig. The sluCubic 150 mm × 150 mm × 150 mm specimens were used for compressive strength tests, 70 × 70 × 250 mm prisms were used for flexural strength tests, and Ø150 mm × 300 mm cylinders were used for the splitting tensile strength and shear strength tests. For every single property, three specimens were tested, and the average was recorded. All specimens were kept in their molds for 24 h at a temperature of 22 ± 1 °C, after which they were de-molded and immersed in water for 7 days, and then kept under laboratory conditions at 20 ± 2 °C and 35% relative humidity, until the testing date at the age of 28 days.P) for each test, the compressive, splitting tensile, flexural, and shear strengths were calculated in MPa using the equations presented in Compressive strength, splitting tensile strength, and three-point bending tests were conducted in accordance with BS EN 12390-3 , CEN EN Finally, twelve reinforced concrete beams were tested: four of them reinforced with GFRP, four of them reinforced with BFRP, and the last four reinforced with steel bars. For each reinforcement type, two beams were tested: two from concrete LW0% and two from concrete LW100%. The adopted nomenclature for the beams was the following: St-LW0% and St-LW100% for the steel-reinforced beams with 0% and 100% of LWA, respectively. Gl-LW0% and Gl-LW100% for the GFRP beams with 0% and 100% of LWA, respectively, and finally Ba-LW0% and Ba-LW100% for the BFRP beams with 0% and 100% of LWA, respectively.fρ), balanced reinforcement ratio (fbρ), reinforcement types and numbers, beams nomenclature, and concrete type.β1—0.65 (for high strength concrete).fuf—design tensile strength of the reinforcement bars (MPa).fE—modulus of elasticity of the reinforcement bars (MPa).cuε—ultimate strain of the concrete.c’f—specified compressive strength of the concrete.b—width of the beam.d—distance from extreme fiber in compression to the center of reinforcement (mm).fA—area of longitudinal reinforcement (mm2).The beams had dimensions of width/height/length = 100/150/1100 mm. The beams were reinforced with two bars as bottom longitudinal reinforcement, with a clear concrete cover of 30 mm, while no shear reinforcement was used. The beams were simply supported with a clear span of 900 mm and loaded in three-point bending using a hydraulic jack located at the center of the beam, allowing for the beams to deflect under monotonic load. A 600 kN hydraulic actuator anchored to an independent steel frame was used to apply a monotonic increasing load at the mid-span of the beam. The beams were tested under displacement-controlled loading at the rate of 1 mm/min, until failure of the beam by reinforcement rupture or concrete crushing. The mid-span deflections were measured using linear variable differential transformers (LVDTs). Two LVDTs were used to measure and record the vertical deflection at the mid-span. A load cell and the LVDTs were connected to a data logger to obtain vertical deflection readings and applied load. The beams’ dimensions and reinforcement are shown in The results of physical–mechanical property tests are given in Similar to workability, the mechanical properties of LWC also exhibit a decrease with an increasing percentage of LWA. In terms of compressive strength, adding 50% and 100% of LWA decreased compressive strength by 23% and 28%, respectively. This reduction in compressive strength is most likely due to the high porosity of the expanded clay LWA and its consequent low density and crushing strength compared to NA. Applying the Eurocode 2 classification, the concretes LW0%, LW50%, and LW100% could be classified as C70/77, LC50/55, and LC45/50, respectively.As for splitting tensile strength, the reduction was 17% and 25% for 50% and 100% of LWA substitution, respectively, whereas, in the case of flexural strength, the decrease was 10% and 20% for 50% and 100% of LWA substitution, respectively. The decreases in tensile strength are slightly smaller than those for compressive strength since aggregate crushing strength is not the determining parameter, but rather their tensile strength and the cement paste–aggregate bond. However, due to the higher porosity and water absorption of LWA, the pore area and thickness of the interfacial zone are increased in LWC, preventing cement particles from binding tightly to the expanded clay LWA ,17,39.Finally, in terms of shear strength, the reduction was 20% and 34% for LW50% and LW100%, respectively, relative to LW0%. The greater brittleness of LWA has been previously postulated as an explanation for the reduction in shear strength of LWC compared with normal weight concrete . NonetheIn order to investigate and compare the flexural behaviors of 0%LWA and 100%LWA beams reinforced with steel, GFRP, and BFRP bars, a three-point bending test was applied on two beams of each concrete type with each reinforcement type. A load cell and two LVDTs were placed at the mid-span and connected to the data logger to get the vertical deflection values. In accordance, the LVDTs were connected to an automatic data-acquisition system, which was connected to a computer to record the loading, deflections, and strains in the reinforcement and the surrounding concrete .Load–displacement graphs were generated on the computer while performing the three-point bending test over a clear span of 900 mm. Furthermore, crack propagation and failure type of the specimens were observed. The load–displacement relationships of St-0%LWA and St-100%LWA beams are shown in Both Gf-0%LWA and Gf-100%LWA faced a sudden concrete crushing failure after reaching the maximum load . This beBf-0%LWA and Bf-100%LWA beams behaved similarly to the specimens reinforced with GFRP bars, where the load and the displacement increased linearly until reaching the failure point, and hints the studied beams collapsed, as is observed in In agreement with the results of Akbarzadeh Bengar et al. (2021) , the stuCompared to steel reinforced beams, BFRP beams are lower in post crack stiffness, due to the lower modulus of elasticity of BFRP bars The pre-posting stiffness of steel reinforced beams is higher compared to BFRP beams or GFRP beams, where the first cracking loads of St-0%LWA and St-100%LWA are higher than Bf-0%LWA and Bf-100%LWA by 29% and 44%, respectively. It is also worth mentioning that the first cracking load of the GFRP beams is higher than that of BFRP beams by around 38%.L/100–L/120) for enabling detection prior to failure. As such, they can be considered suitable for structural use.Although the FRP-reinforced beams exhibited more abrupt and sudden failures, they still reached considerable loads, relative to the steel-reinforced beams, as well as sufficiently high deflections (in the order of crM) calculated using the ACI 440.1R [crM—first cracking moment.λ—(= 0.75) modification factor reflecting the reduced mechanical properties of LWC, and λ = 1.0 for normal weight concrete.g—Imoment of inertia of the gross section.t—Ydistance from the centroid axis of the gross section, neglecting reinforcement, to the tension face.The experimental results of the cracking moment of steel-reinforced beams are higher compared to any of the fiber reinforced polymer beams, and that is due to their higher flexural capacity and the modulus of elasticity of steel bars. I 440.1R  expressicrM of the beams, where St-0%LWA, Gf-0%LWA, and Bf-0%LWA have a higher crM by 26%, 24%, and 35% compared with St-100%LWA, Gf-100%LWA, and Bf-100%LWA, respectively. The crM predicted from the ACI code equation is lower or equal to the experimental values, where the theoretical crM values of St-0%LWA and Gf-0%LWA are lower by 31% and 1% compared to the experimental values. In accordance, the theoretical crM of St-100%LWA and Bf-100%LWA are 41% and 17% lower compared with the experimental crM values.For all the beams, it shows that LWA decreases the While applying the three-point bending test on the reinforced beams, vertical cracks started to occur at the bottom surface of the tested beams, especially in the case of normal weight concrete beams, as they occurred initially due to the early shrinkage of the tested specimens. St-0%LWA developed flexural cracks due to the tensile stresses, while St-100%LWA faced diagonal shear cracks with an angle of around 45°, thereby, with load increment, the shear cracks reached to the point load and failure occurred. GFRP beams, in both cases, faced a combination of flexural and shear cracks patterns with load increment, due to shear and tensile stresses. For BFRP beams, flexural cracks started to form in the bottom of the beam, followed by the occurrence of shear cracks, where they propagated toward the loading point. At the final stage of loading, crack width increased, and the cracks propagated towards the compression zone, reached the point load, and thus the reinforced beams failed.The inclinations of the critical shear cracks of Bf-100%LWA were in the range of 43–48°, while they were in the range of 56–66° for normal weight beams. The beams failed in diagonal shear failure due to the absence of shear reinforcement, and since the transverse reinforcement was not applied, therefore, the development of inclined cracks caused the shear and brittle failure. In accordance, horizontal cracks were observed along with the longitudinal tensile reinforcement of the BFRP beams due to the absence of the anchorage reinforcement, but their occurrence did not affect the failure mode. These cracks are generated due to the high deformation of the BFRP, causing a slippage between the reinforcement bars and the surrounding concrete. Sketches for the cracking patterns at failure for all the beams are shown in Fresh- and hardened-state physical and mechanical properties of SCC decreased by increasing the dose of expanded clay LWA.By using GFRP or BFRP bars, the maximum load and maximum deflection of beams are reduced compared to the beams reinforced with steel bars. However, in LWC, the effect of FRPs on the maximum deflection is smaller compared with the effect in normal weight concrete or LWC beams reinforced with steel bars.For LWC, the beams reinforced by GFRP or BFRP perform similarly in terms of maximum load, maximum deflection, crack width, and cracking moment. The maximum deflection of the beams reinforced by steel bars is decreased when LWC is used.In this study, the combined use of expanded clay LWA and FRP reinforcement was investigated and the effects of these materials on the physical–mechanical properties of LWC and its structural behavior were investigated. Based on the obtained experimental results, the following conclusions can be reached:The results of this study can provide additional support for the use of innovative materials such as LWA and FRP reinforcement. Further studies should be carried out to investigate other aspects of both material and structural behavior, in particular bond characterization tests, to further deepen the knowledge and understanding of LWC reinforced with innovative reinforcements.


Backgrounds: The purpose of this study is to present our clinical experience using the Ilizarov bone transfer technique and free-flap technique in the reconstruction of large tibial bone and soft tissue defects, including an evaluation of both the management of postoperative complications and long-term outcomes. Methods: From January 2010 to May 2020, 72 patients with tibia bone and soft tissue defects were retrospectively evaluated. Either an anterolateral thigh perforator flaps (ALTP) or latissimus dorsi musculocutaneous flaps (LD), solely or in combination, were used to cover soft tissue defects. Once the flap was stabilized, an Ilizarov external fixator was applied to the limb. Follow-up was postoperatively performed at 1, 3, 6, 9, and 12 months. Results: Postoperatively, there were two cases of total and five of partial flap necrosis, and two cases of subcutaneous ulcers, which were caused by vascular crisis, infection, and hematoma, respectively. All the patients underwent Ilizarov external fixator surgery after flap recovery. A total of 16 complications occurred, including 3 cases of simple needle tract infection (antibiotic treatment) and 13 cases of complications requiring reoperation. A correlation factor analysis revealed that the main factors affecting the healing time were the defect length and operative complications. All patients with complications treated with the vascularized iliac flap eventually healed completely. Conclusions: The Ilizarov method used together with an ALTP, LD, or a combination thereof yields good clinical results for repairing large bone and soft tissue defects of the tibia, thus reducing the incidence of amputations. However, longer treatment times may be involved, and postoperative complications can occur. The vascularized iliac flap may be a suitable choice for the treatment of postoperative complications of this type of Ilizarov bone transport. Open and comminuted fractures of lower extremities caused by high-energy and severe trauma, usually accompanied by severe peripheral soft tissue injury or defects, as well as bone and soft tissue necrosis and infection, are thorny problems in surgery . WithoutWith the development of perforator flap technique, the damage to the donor site can be significantly reduced, and the application scope is becoming increasingly wide. “Free flap” is the main method to repair large soft tissue defects, and latissimus dorsi musculocutaneous (LD) and anterolateral thigh perforator (ALTP) flaps are commonly used ,4,5. TheAt present, there are a variety of repair methods for bone defects, including allografts , cancellIn this study, a retrospective study was conducted to collect the data of patients with severe large tibial bone defects combined with soft tissue defects who were treated in our department from January 2010 to May 2020. Specifically, the purpose of this report was to evaluate the clinical efficacy of Ilizarov bone transport combined with free-flap transplantation, the management of postoperative complications, and long-term outcomes.n = 54), crush injury (n = 11), and agricultural accidents (n = 7). Patient details are shown in Seventy-two patients with lower extremity tibia and soft tissue defects were treated using either an ALTP, LD, or a combination thereof to cover soft tissue defects. Ilizarov bone transport was used to reconstruct bone defects from January 2010 to May 2020. A total of 63 male patients and 9 female patients were included in this study. The age of patients ranged from 8 to 57 years . The original mechanisms of injury were traffic accidents , and the size of the bone defect ranged from 5 to 18 cm .Of the included patients, 28 were admitted to the emergency department after direct trauma and 44 had a history of surgical treatment, including an open reduction with internal and external fixation before admission. After debridement, the size of the soft tissue defects ranged from 50.0 to 360.0 cmAfter the initial debridement, all patients were treated by general external fixation. Flap coverage was performed when the wound was deemed clean. Massive tibial bone defects were usually accompanied by large soft tissue defects, and thus, an ALTP, LD, or a combination thereof were used to cover large defects .After free-flap stabilization , the temporary external fixator was replaced by an Ilizarov external fixator ,20. The The patients underwent supervised daily physiotherapy, including active and passive range-of-motion exercises for the knee and ankle. Standing and walking, with a gradual shift from partial to full weight-bearing, was encouraged. Distraction commenced on postoperative day 7 at a rate of 1 mm/d and continued in four equal increments until the desired length had been achieved. Consolidation was considered sufficient when the formation of a bridging callus was visible on three of four visible cortices in the anteroposterior and lateral radiographs, and when tenderness at the fracture site and pain during full weight-bearing without connecting rods were no longer present. After confirming consolidation, the apparatus was removed under local anesthesia in the outpatient clinic.The postoperative complications of Ilizarov bone transport included fracture nonunion, intolerability, and soft tissue interposition (when reoperation was required to remove ischemic bone and/or embedded soft tissue before vascularized iliac bone flap transplantation) in addition to refracture (with a cancellous bone graft of iliac crest).Demographic and intraoperative data, early complications, and long-term follow-up results were collected. Follow-up was performed at 1, 3, 6, 9, and 12 months postoperatively. Confirmation of bone healing  was monitored for up to 1 year. The cosmetic appearances of the recipient and donor sites were subjectively evaluated by the guardian and objectively by a blinded third-party observer according to a scale of 1 (excellent) to 4 (poor). The bone and functional results were assessed by ASAMI criteria  at the lt test (a comparison of two independent samples) or a one-way ANOVA-LSD test (a comparison of three independent samples) were used to compare the factors related to fracture healing time. Statistical analysis was performed by SPSS 20.0 software . A p-value of p < 0.05 was considered to indicate statistically significant differences.Descriptive statistics of preoperative, intraoperative, and postoperative basic conditions were performed in this study. Quantitative data were expressed as mean ± standard deviation, and qualitative data were expressed as the number of cases. Student’s 2. To cover these soft tissue defects, ALTP flaps were used in 24 patients, LD flaps in 32 patients, and combined flaps  in 16 patients. The flap harvesting time was 74.0 ± 20.2 min, and the total operation time was 275.8 ± 55.1 min. There were two cases of total flap necrosis, five cases of partial flap necrosis, and two cases of subcutaneous ulcers, caused by vascular crisis, infection, and hematoma, respectively. Following vascular exploration, re-flap surgery, and dressing change, all flaps successfully healed. There was a delayed healing of the donor site in two patients in which healing occurred after dressing change.The follow-up time ranged from 25 to 49 months . The mean soft tissue defect size was 198.8 ± 50.8 cmAll patients underwent Ilizarov external fixator surgery after the flap was stabilized . The operation time was 60.6 ± 8.4 min, the external fixator was carried for 21.3 ± 5.6 months, the external fixation index was 62.4 ± 11.2 d/cm, and the bone healing time was 23.3 ± 5.6 months. Based on the ASAMI scoring, excellent and good ratings of bone results were achieved in 90.3% (65/72) of cases, and a functional result in 70.8% (51/72). Satisfaction with the cosmetic appearance of patients’ lower extremities was evaluated by their guardians and third-party blind observers, and the rates for excellent and good results were 70.8% and 68.1%, respectively.During the follow-up period, 16 complications occurred, including 3 cases of simple needle tract infection (antibiotic treatment) and 13 cases of complications requiring reoperation. A total of 21 patients could not tolerate the external fixator because of the long treatment time and the severity of complications. The detailed management of complications requiring reoperation is shown in p < 0.05, p < 0.05, p < 0.05, A univariate analysis showed that the time of bone healing was related to age, bone defect length, size of the soft tissue defect, and postoperative complications  To decrease the treatment period, Yang et al.  and BorzThe Ilizarov method combined with free flap technique yielded good clinical results in repairing large bone and soft tissue defects of the tibia, thus reducing the incidence of amputations. However, there are still the following shortcomings: (1) Compared with simple soft tissue defects, the defect area and wound severity in this study were more serious, resulting in a relatively increased risk of postoperative flap complications. (2) Since the length of bone healing time was closely related to the length of the bone defect and the occurrence of complications, the longer the treatment time, the higher the risk of postoperative complications, which cannot be tolerated by most patients. In order to solve the corresponding complications, we used the vascularized iliac bone flap in this study and achieved good results. Therefore, our center has begun to gradually explore the combination of the Ilizarov bone transport technique with vascularized iliac bone flap transplantation to reduce bone healing time and reduce the incidence of complications; however, its efficacy needs to be further observed.