Noninvasive Assessment of hiPSC Differentiation toward Cardiomyocytes Using Pretrained Convolutional Neural Networks and the Channel Pruning Algorithm.

Human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes (hiPSC-CMs) offer versatile applications in tissue engineering and drug screening. To facilitate the monitoring of hiPSC cardiac differentiation, a noninvasive approach using convolutional neural networks (CNNs) was explored. HiPSCs were differentiated into cardiomyocytes and analyzed using the quantitative real-time polymerase chain reaction (qRT-PCR). The bright-field images of the cells at different time points were captured to create the dataset. Six pretrained models (AlexNet, GoogleNet, ResNet 18, ResNet 50, DenseNet 121, VGG 19-BN) were employed to identify different stages in differentiation. VGG 19-BN outperformed the other five CNNs and exhibited remarkable performance with 99.2% accuracy, recall, precision, and F1 score and 99.8% specificity. The pruning process was then applied to the optimal model, resulting in a significant reduction of model parameters while maintaining high accuracy. Finally, an automation application using the pruned VGG 19-BN model was developed, facilitating users in assessing the cell status during the myocardial differentiation of hiPSCs.

Assessment of Vigilance Level during Work: Fitting a Hidden Markov Model to Heart Rate Variability.

This study aimed to enhance the real-time performance and accuracy of vigilance assessment by developing a hidden Markov model (HMM). Electrocardiogram (ECG) signals were collected and processed to remove noise and baseline drift. A group of 20 volunteers participated in the study. Their heart rate variability (HRV) was measured to train parameters of the modified hidden Markov model for a vigilance assessment. The data were collected to train the model using the Baum-Welch algorithm and to obtain the state transition probability matrix A^ and the observation probability matrix B^. Finally, the data of three volunteers with different transition patterns of mental state were selected randomly and the Viterbi algorithm was used to find the optimal state, which was compared with the actual state. The constructed vigilance assessment model had a high accuracy rate, and the accuracy rate of data prediction for these three volunteers exceeded 80%. Our approach can be used in wearable products to improve their vigilance level assessment functionality or in other fields that have key positions with high concentration requirements and monotonous repetitive work.

Effects of aircraft tray table height and neck posture on passenger comfort: A study of the economy class cabin.

BACKGROUND: The tray table in economy class air travel may cause excessive neck flexion and discomfort in passengers. OBJECTIVE: The purpose of this study is to examine the influence of different tray table heights on the neck posture and discomfort perception of passengers. METHODS: A passenger experience survey was used to determine the passengers' view that the tray table was not high enough, and that most passengers were dissatisfied with the overall comfort evaluation of the tray table, especially passengers with obesity. Three head-neck angles and discomfort perceptions of six body parts in 58 participants were recorded by neck posture 3D scanning and perceived level of discomfort assessment, respectively. RESULTS: Tray tables at the original height (68 cm) caused unnatural neck posture and discomfort in participants. Raising the tray table can improve the neck posture of participants and reduce discomfort. However, raising the tray table too high will cause more shoulder discomfort in participants. Based on the results, 78 (±2) cm is suggested as the suitable thresholds range of tray tables for economy class air travel. CONCLUSION: The results and findings of this study could provide a theoretical base for the optimization of tray table design.

A possible covalent xanthine oxidase inhibitor TS10: Inhibition mechanism, metabolites identification and PDPK assessment.

Xanthine oxidase (XO) inhibitors are widely used in the control of serum uric acid levels in the clinical management of gout. Our continuous efforts in searching novel amide-based XO inhibitors culminated in the identification of N-(4-((3-cyanobenzyl)oxy)-3-(1H-tetrazol-1-yl)phenyl)isonicotinamide (TS10), which exhibited comparable in vitro inhibition to that of topiroxostat (TS10, IC50 = 0.031 µM; topiroxostat, IC50 = 0.020 µM). According to the molecular modeling, we speculated that, as well as topiroxostat, TS10 would be biotransformed by XO to yield TS10-2-OH. In this work, TS10-2-OH was successfully identified in XO targeted metabolism study, demonstrated that TS10 underwent a covalent binding with XO via a TS10-O-Mo intermediate after anchoring in the XO molybdenum cofactor pocket. Furthermore, TS10-2-OH is a weak active metabolite, and its potency was explained by the molecular docking. In metabolites identification, TS10 could be oxidized by CYP2C9, CYP3A4 and CYP3A5 to generate two mono-hydroxylated metabolites (not TS10-2-OH); and could occur degradation in plasma to mainly generate a hydrolytic metabolite (TS10-hydrolysate). In pharmacokinetic assessment, the low oral system exposure was observed (Cmax = 14.73 ± 2.66 ng/mL and AUClast = 9.17 ± 1.42 h⋅ng/mL), which could be explained by the poor oral absorption property found in excretion studies. Nonetheless, in pharmacodynamic evaluation, TS10 exhibited significant uric acid-lowering effect after oral administration in a dose-dependent manner. Briefly, in addition to allopurinol and topiroxostat, TS10 is possibly another explicitly mechanism-based XO inhibitor with powerful covalent inhibition.

Health risk and disease burden attributable to long-term global fine-mode particles.

Particulate matter 2.5 (PM2.5) pollution has long been a global environmental problem and still poses a great threat to public health. This study investigates global spatiotemporal variations in PM2.5 using the newly developed satellite-derived PM2.5 dataset from 1998 to 2018. An integrated exposure-response (IER) model was employed to examine the characteristics of PM2.5-related deaths caused by chronic obstructive pulmonary disease (COPD), ischemic heart disease (IHD), lung cancer (LC), and stroke in adults (age≥25), as well as lower respiratory infection (LRI) in children (age≤5). The results showed that high annual PM2.5 concentrations were observed mainly in East Asia and South Asia. Over the 19-year period, PM2.5 concentrations constantly decreased in developed regions, but increased in most developing regions. Approximately 84% of the population lived in regions where PM2.5 concentrations exceeded 10 µg/m3. Meanwhile, the vast majority of the population (>60%) in East and South Asia was consistently exposed to PM2.5 levels above 35 µg/m3. PM2.5 exposure was linked to 3.38 (95% UI: 3.05-3.70) million premature deaths globally in 2000, a number that increased to 4.11 (95% UI: 3.55-4.69) million in 2018. Premature deaths related to PM2.5 accounted for 6.54%-7.79% of the total cause of deaths worldwide, with a peak in 2011. Furthermore, developing regions contributed to the majority (85.95%-95.06%) of PM2.5-related deaths worldwide, and the three highest-ranking regions were East Asia, South Asia, and Southeast Asia. Globally, IHD and stroke were the two main contributors to total PM2.5-related deaths, followed by COPD, LC, and LRI.

Structure-based virtual screening of CYP1A1 inhibitors: towards rapid tier-one assessment of potential developmental toxicants.

Cytochrome P450 1A1 (CYP1A1) metabolizes estrogens, melatonin, and other key endogenous signaling molecules critical for embryonic/fetal development. The enzyme has increasing expression during pregnancy, and its inhibition or knockout increases embryonic/fetal lethality and/or developmental problems. Here, we present a virtual screening model for CYP1A1 inhibitors based on the orthosteric and predicted allosteric sites of the enzyme. Using 1001 reference compounds with CYP1A1 activity data, we optimized the decision thresholds of our model and classified the training compounds with 68.3% balanced accuracy (91.0% sensitivity and 45.7% specificity). We applied our final model to 11 known CYP1A1 orthosteric binders and related compounds, and found that our ranking of the known orthosteric binders generally agrees with the relative activity of CYP1A1 in metabolizing these compounds. We also applied the model to 22 new test compounds with unknown/unclear CYP1A1 inhibitory activity, and predicted 16 of them are CYP1A1 inhibitors. The CYP1A1 potency and modes of inhibition of these 22 compounds were experimentally determined. We confirmed that most predicted inhibitors, including drugs contraindicated during pregnancy (amiodarone, bicalutamide, cyproterone acetate, ketoconazole, and tamoxifen) and environmental agents suspected to be endocrine disruptors (bisphenol A, diethyl and dibutyl phthalates, and zearalenone), are indeed potent inhibitors of CYP1A1. Our results suggest that virtual screening may be used as a rapid tier-one method to screen for potential CYP1A1 inhibitors, and flag them out for further experimental evaluations.

[Concentration Analysis and Health Risk Assessment of Air Pollutants in Newly Decorated Public Places in Xi'an].

In order to understand the levels of indoor air pollution and health risks in public places, our research group conducted air quality monitoring and human health risk assessments for five types of public places (offices, classrooms, laboratories, banks, and hospitals) in Xi'an City from December 2017 to July 2020. The test items included formaldehyde, benzene, toluene, xylene, n-butyl acetate, ethylbenzene, styrene, n-undecane, and total volatile organic compounds (TVOC). The results showed that formaldehyde had the highest exceedance rate (59.4%), followed by toluene, TVOC, benzene, and xylene. Among the five types of public places, hospitals had the highest rate of pollutants exceeding the standard (46.7%), and the main pollutants exceeding the standard were formaldehyde, benzene, and toluene. The results showed that the concentrations of formaldehyde and TVOC were positively correlated with temperature and humidity. The health risk assessment results showed that there were carcinogenic risks of formaldehyde and benzene in different places; people working in banks had a higher risk of formaldehyde carcinogenesis, and those working in hospitals had a higher risk of benzene carcinogenesis. This study provides a reference for the level of indoor air pollution in public places in Xi'an City, and is of great significance to the health risk research of related populations.

Disparities of perceived wellness by smoking and professional status among young individuals in Brasov, Brasov County, Romania.

OBJECTIVE: We aimed to evaluate the association of risk factors such as smoking and professional status (students vs employed) as determinants of disparities in perceived wellness among Romanian individuals. METHODS: We conducted a cross-sectional study in which 145 participants were enrolled from December 2017 to February 2018, in Brasov, Brasov County, Transylvania, Romania. We used a simplified Perceived Wellness Survey model to measure the holistic individual perceived wellness status by professional and smoking status. Basic descriptive and multivariate analyses of variance were used to assess and contrast participants' characteristics and wellness score distributions. A factor analysis was used to estimate Kaiser-Meyer-Olkin values and calculate standardized Cronbach's coefficients. RESULTS: The average age of our participants was 27.7 years. Compared with students, more employed participants tended to smoke electronic cigarettes (p < 0.0001). The association between professional status and perceived wellness was non-significant. Employed participants were nevertheless more likely to regard themselves as more proactive in dealing with emotional (p < 0.0001), environmental (p = 0.0042), and spiritual issues (p = 0.0039). Perceived physical wellness was statistically different by smoking status (p < 0.0001). CONCLUSION: Among our study participants, there is an association between smoking and perceived wellness. For emotional, environmental, and spiritual domains, employed participants are more likely to regard themselves as more confident. Our study demonstrates the direct application of the Perceived Wellness Survey model in predicting the disparities of perceived wellness among young individuals. It allows health agencies to target disparity interventions among populations with high risk of low perceived wellness.

Antimalarial proteasome inhibitor reveals collateral sensitivity from intersubunit interactions and fitness cost of resistance.

We describe noncovalent, reversible asparagine ethylenediamine (AsnEDA) inhibitors of the Plasmodium falciparum proteasome (Pf20S) ß5 subunit that spare all active subunits of human constitutive and immuno-proteasomes. The compounds are active against erythrocytic, sexual, and liver-stage parasites, against parasites resistant to current antimalarials, and against P. falciparum strains from patients in Africa. The ß5 inhibitors synergize with a ß2 inhibitor in vitro and in mice and with artemisinin. P. falciparum selected for resistance to an AsnEDA ß5 inhibitor surprisingly harbored a point mutation in the noncatalytic ß6 subunit. The ß6 mutant was resistant to the species-selective Pf20S ß5 inhibitor but remained sensitive to the species-nonselective ß5 inhibitors bortezomib and carfilzomib. Moreover, resistance to the Pf20S ß5 inhibitor was accompanied by increased sensitivity to a Pf20S ß2 inhibitor. Finally, the ß5 inhibitor-resistant mutant had a fitness cost that was exacerbated by irradiation. Thus, used in combination, multistage-active inhibitors of the Pf20S ß5 and ß2 subunits afford synergistic antimalarial activity with a potential to delay the emergence of resistance to artemisinins and each other.

A National County-Level Assessment of U.S. Nursing Facility Characteristics Associated with Long-Term Exposure to Traffic Pollution in Older Adults.

Long-term exposure to ambient air pollution increases disease risk in older adults. Nursing facilities located near major roadways potentially expose older adults to traffic pollution. No studies, however, have described the association between nursing facilities and traffic pollution. We obtained data on facility- and census-tract-level characteristics of 15,706 U.S. facilities from the Medicare Nursing Home Compare datasets. We calculated distance to major roadways and traffic density for each facility. In the contiguous U.S. (as of 2014), 345,792 older adults, about 27% of residents in non-hospital facilities, lived within 150 m major roadways (A1 or A2) in 3876 (28% of sampled) facilities. Nationally, for-profit facilities, high-occupancy facilities, and facilities in census tracts with higher percentages of minorities were more likely to have higher exposure to traffic. Counties in Virginia, New York City, and Rhode Island have the highest percent of residents and facilities near major roads. Nationally, over one-quarter of sampled facilities are located near major roadways. Attributes potentially associated with higher exposure to traffic included "for-profit" and "higher minority census tract". Proximity to major roadways may be an important factor to consider in siting nursing facilities. Our results inform potential intervention strategy at both county and facility level.

Lived Experiences of Novice Male Nurses in Taiwan.

PURPOSE: Nursing remains a female-dominated profession around the world. The masculinity and male identity of men who choose nursing careers is questioned by the general public in many countries. Few studies report the situation of novice male nurses at their first year. The purpose of this study was to explore the lived experience of novice male nurses when they first enter the workplace. DESIGN AND METHOD: A qualitative descriptive study was conducted using purposive and snowball sampling for recruitment. Fourteen participants, 21 to 25 years old, were recruited, all of whom had at least 5 months of work experience. On average, in-depth, face-to-face interviews lasted 1 hour, with more than one follow-up telephone interview per participant. FINDINGS: The following six themes emerged from the transcribed verbatim data based on content analysis: choosing appropriate work departments based on personality and needs, facing the pressure and frustration of independent work, getting help, obtaining acceptance among female cliques, reflecting on the relationship between gender and profession, and concerns about dependents and financial needs. CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: This study addresses masculinity issues and gender stereotyping. In addition, male nurses were very concerned about their career options and development and the likelihood of promotion. This research not only has implications for better understanding of novice male nurses' needs and the challenges in their social life but also makes suggestions for nursing practice to attract and keep more male nurses in the nursing profession. The results illustrate how culturally congruent nursing care can be achieved when we more concern male nurses' role pressure and address traditional gender sensitivity to promote male nurses' career development.

Gender differences? Internet use and parent-child communication about sex toward sexual attitudes among early adolescents in Taiwan.

BACKGROUND: With the progress of information technology, early adolescents are able to access sex-related information through the Internet easily. This information has been shown to have a significant influence on the sexual health of this population. In addition, parent-child communications about sex affect the sexual health of adolescents. Few empirical studies have focused on early adolescents and gender differences. PURPOSE: This study explores gender differences between early adolescents in terms of the use of the Internet to obtain sex-related information, parent-child communication, and sex-related knowledge and attitudes. METHODS: This cross-sectional and comparative study uses an analysis of covariance and a hierarchical regression for data analysis. The researchers recruited 457 sixth-grade boys (n = 204) and girls (n = 253) in southern Taiwan as participants and used a structured questionnaire to collect data. RESULTS: Participants exhibited significant differences in terms of Internet usage behavior, parent-child communications about sex, and sex-related knowledge and sexual attitudes. The male participants spent more time on "recreation and entertainment" activities on the Internet, whereas their female peers spent significantly more time searching for information. Regarding parent-child communications about sex, girls had better mother-child communications than boys. In addition, no gender-based difference was found for father-child communications about sex. The knowledge of physical changes occurring during puberty and of menstrual healthcare among female participants was superior to their male counterparts. Girls had a more informed sexual attitude, particularly with regard to issues of gender roles, relationships with the opposite gender, and the social aspects of sex. Sex-related knowledge and parent-child communication about sex were the two major predictors of sexual attitudes for boys and girls, respectively. CONCLUSIONS: To develop healthy sexual attitudes among early adolescents, nursing professionals, families, and schools should enhance sex-related knowledge and parent-child communications, especially with boys. Early adolescence is a key time to provide sex education and Internet-safety education to both boys and girls to improve their sexual health. This study may serve as a reference for families, schools, researchers, and policymakers for promoting the sexual health of early adolescents.

The Ebola threat: China's response to the West African epidemic and national development of prevention and control policies and infrastructure.

There is growing concern in West Africa about the spread of the Ebola hemorrhagic fever virus. With the increasing global public health risk, a coordinated international response is necessary. The Chinese government is prepared to work in collaboration with West African countries to assist in the containment and control of the epidemic through the contribution of medical expertise and mobile laboratory testing teams. Nationally, China is implementing prevention programs in major cities and provinces, the distribution of Ebola test kits, and the deployment of a new national Ebola research laboratory.

[Symptom assessment and management of pregnancy-related nausea and vomiting].

Pregnancy-related nausea and vomiting are uncomfortable symptoms. These symptoms are consistent across cultures, may persist for extended periods of time during the early stage of pregnancy, and may adversely affect expectant mothers and their fetuses. Further, these symptoms may negatively impact mother and infant health and increase medical costs in the absence of effective diagnosis and symptom management. Relevant literature and research is integrated to propose subjective and objective approaches to assessing symptoms such as a index of nausea, vomiting and retching (INVR) and to develop a preliminary clinical management model that prioritizes using a non-pharmacological strategy to treat mild and moderate nausea and vomiting. Article recommendations provide a practical clinical care reference to help pregnant women successfully pass through this uncomfortable stage and achieve better quality-of-life and birth outcomes.

Optimized atomic statistical potentials: assessment of protein interfaces and loops.

MOTIVATION: Statistical potentials have been widely used for modeling whole proteins and their parts (e.g. sidechains and loops) as well as interactions between proteins, nucleic acids and small molecules. Here, we formulate the statistical potentials entirely within a statistical framework, avoiding questionable statistical mechanical assumptions and approximations, including a definition of the reference state. RESULTS: We derive a general Bayesian framework for inferring statistically optimized atomic potentials (SOAP) in which the reference state is replaced with data-driven 'recovery' functions. Moreover, we restrain the relative orientation between two covalent bonds instead of a simple distance between two atoms, in an effort to capture orientation-dependent interactions such as hydrogen bonds. To demonstrate this general approach, we computed statistical potentials for protein-protein docking (SOAP-PP) and loop modeling (SOAP-Loop). For docking, a near-native model is within the top 10 scoring models in 40% of the PatchDock benchmark cases, compared with 23 and 27% for the state-of-the-art ZDOCK and FireDock scoring functions, respectively. Similarly, for modeling 12-residue loops in the PLOP benchmark, the average main-chain root mean square deviation of the best scored conformations by SOAP-Loop is 1.5 Å, close to the average root mean square deviation of the best sampled conformations (1.2 Å) and significantly better than that selected by Rosetta (2.1 Å), DFIRE (2.3 Å), DOPE (2.5 Å) and PLOP scoring functions (3.0 Å). Our Bayesian framework may also result in more accurate statistical potentials for additional modeling applications, thus affording better leverage of the experimentally determined protein structures. AVAILABILITY AND IMPLEMENTATION: SOAP-PP and SOAP-Loop are available as part of MODELLER (http://salilab.org/modeller).

[Family caregiver issues: gender, privacy, and public policy perspectives].

Due to the phenomenon of Taiwan'saging population has made, long-term care has become an issue of increasingly emphasized importance. According to the statistics, the family takes responsibility for most long-term care duties and more than 70% of primary family caregivers are female. In the past, because of gender-based divisions of labor and gender role expectations made, it was taken for granted that females would be the socially preferred family caregivers. Those men who devoting in themselves to such work were regarded as a rare precious. As such, family care signified entailed different life experiences for males and females. Over the years, amendments to the civil code have recognized family care contributions, and the allowance for caregivers underlines that care responsibilities have shifted away from the family to society. Traditional gender divisions of labor today are significantly more blurred; family structures have become smaller in size; female labor in the workplace has increased; and ten-year long-term care plans and long-term care insurance have been successively implemented. These transformations will make labor outsourcing more and more popular and transform family care from a private problem to a pubic policy issue. In the future, family caregivers require consideration and support on a sustained basis. It is also important to improve and monitor the quality of care services. Nurses, the major professional members of long-term care teams, should be concerned over the issue of family care while providing nursing care. They should include family caregivers in the care plan so that they can make sure that patients receive comprehensive and constant care in order to enhance the overall quality of nursing care.

Basic needs and their predictors for intubated patients in surgical intensive care units.

OBJECTIVE: This study was conducted to investigate the basic needs and communication difficulties of intubated patients in surgical intensive care units (ICUs) and to identify predictors of the basic needs from the patient characteristics and communication difficulties. METHODS: In this descriptive correlational study, 80 surgical ICU patients were recruited and interviewed using 3 structured questionnaires: demographic information, scale of basic needs, and scale of communication difficulties. RESULTS: The intubated patients were found to have moderate communication difficulties. The sense of being loved and belonging was the most common need in the intubated patients studied (56.00 standardized scores). A significantly positive correlation was found between communication difficulties and general level of basic needs (r = .53, P < .01), and another positive correlation was found between the length of stay in ICUs and the need for love and belonging (r = .25, P < .05). The basic needs of intubated patients could be significantly predicted by communication difficulties (P = .002), use of physical restraints (P = .010), lack of intubation history (P = .005), and lower educational level (P = .005). These 4 predictors accounted for 47% of the total variance in basic needs. CONCLUSION: The intubated patients in surgical ICUs had moderate basic needs and communication difficulties. The fact that the basic needs could be predicted by communication difficulties, physical restraints, and educational level suggests that nurses in surgical ICUs need to improve skills of communication and limit the use of physical restraints, especially in patients with a lower educational level.

Predictors of sexual abstinence behaviour in Taiwanese adolescents: a longitudinal application of the transtheoretical model.

AIMS AND OBJECTIVES: To understand (1) the change of stage of changes, self-efficacy, decisional balance and processes of change for sexual abstinence behaviour across a 15-month interval, (2) relations of baseline stage of changes, self-efficacy, decisional balance and processes of change to follow-up stage of changes for sexual abstinence and (3) the important predictors of follow-up stage of changes and transition of stage of changes for sexual abstinence behaviour. BACKGROUND: Examining factors of sexual abstinence behaviour among adolescents can provide useful information in designing sexual abstinence intervention programmes. DESIGN: This study applied a transtheoretical model and used a longitudinal design. METHOD: Anonymous questionnaires were administered to 281 participants at baseline and 15-month follow-up. RESULTS: In summary, 46.3% (n = 130) of the participants were in the same stage, 30.2% (n = 85) regressed and 23.5% (n = 66) progressed their stage from baseline to follow-up. Baseline self-efficacy, decisional balance and processes of change are related to follow-up stage of changes for sexual abstinence. Participants with higher baseline self-efficacy, lower decrease of self-efficacy from baseline to follow-up and lower decrease of decisional balance from baseline to follow-up were more in the definite group (preparation and action stage) at follow-up. Participants with higher baseline decisional balance, lower decrease of decisional balance from baseline to follow-up and lower decrease of self-efficacy from baseline to follow-up were more in the advancement transition group at follow-up. CONCLUSIONS: Focus of interventions could differ according to intervention purpose. Reducing the decrease of self-efficacy and decisional balance across time is important to enable adolescents to be in or progress to better stages across time. RELEVANCE TO CLINICAL PRACTICE: To make adolescents be in later stages at follow-up, increasing baseline self-efficacy is important. If the purpose is to progress the stages, baseline decisional balance should be emphasised. Health care providers should continually boost the self-efficacy and decisional balance of adolescents across time.

A causal model of contraceptive intention and its gender comparison among Taiwanese sexually inexperienced adolescents.

AIMS AND OBJECTIVES: To test latent constructs of social influences, contraceptive attitude and self-efficacy for contraception as a causal model of contraceptive intention among adolescents and to search for possible gender differences in the causal model of contraceptive intention. BACKGROUND: A greater understanding of the causal model of contraceptive intention among sexually inexperienced adolescents will help nurses design contraceptive programmes to improve adolescent contraceptive use when they have sex. Design. This was a cross-sectional study; 770 boys and 685 girls that self-reported not being sexually experienced were selected for this study. METHODS: An anonymous questionnaire was used to collect data. By structural equation modelling using the eqs 6.1 software, a hypothesized structural model of contraceptive intention was tested. FINDINGS: For both genders, social influences affected contraceptive intention indirectly through the contraceptive attitude and self-efficacy for contraception. Contraceptive attitude and self-efficacy for contraception affected contraceptive intention directly. Contraceptive attitude also affected contraceptive intention indirectly through the mediation of self-efficacy for contraception. There were gender differences in the variances of contraceptive intention explained by contraceptive attitude, self-efficacy for contraception and social influences. Nevertheless, the data explain only a low proportion of the variability in contraceptive intention. More causal constructs influencing contraceptive intention should be explored in future. CONCLUSIONS: Personal factors and social influences operate interdependently to influence contraceptive intention among sexually inexperienced adolescents. Gender is a moderator that can modify the influential level of social influences, contraceptive attitude and self-efficacy for contraception on contraceptive intention. RELEVANCE TO CLINICAL PRACTICE: Nurses should operate personal factors and social influences interdependently when they are designing intervention programmes for sexually inexperienced adolescents. To make intervention more effective, nurses also need to provide gender-specific intervention programmes for sexually inexperienced adolescents.

[Assessment on pathophysiological indexes of acute lung injury induced by lipopolysaccharide in rats].

OBJECTIVE: To observe and evaluate the pathophysiological indexes of acute lung injury (ALI) induced by lipopolysaccharide (LPS) in rats. METHODS: Thirty-three Wistar rats were randomly divided into normal control group and experiment group. Respiratory rate , mortality, arterial blood gases, compliance and wet weight of right lung/body weight ratio, tumor necrosis factor-alpha (TNF-alpha) in serum and bronchoalveolar lavage fluid (BALF) were determined 2, 4 and 6 hours after injection of LPS or normal saline in both groups. RESULTS: In the experiment group,the following changes were found. Arterial partial pressure of oxygen (PaO(2)) was reduced to 69.18 mm Hg (1 mm Hg=0.133 kPa), marked blood stasis, and edema in lung tissues could be grossly seen and pathological examination showed that there was a large number of inflammation cell infiltration and edema in interstitial spaces with disappearance of normal construction of alveolar. There was also dilatation of capillaries with congestion and adherent leukocytes. Furthermore, compliance was decreased to 47% of the normal value, and wet weight of right lung/body weight ratio increased to 137% of the normal value. Blood TNF-alpha level increased markedly in serum and BALF. CONCLUSION: Specific pathological changes and decreased PaO(2) over 30% of the baseline value are the main signs of successful reproduction of ALI model in rats. Compliance and weight of right lung/body weight value can also reflect the status of ALI as helpful indexes.