A meta-analysis highlights the cross-resistance of plants to drought and salt stresses from physiological, biochemical, and growth levels

In nature, drought and salt stresses often occur simultaneously and affect plant growth at multiple levels. However, the mechanisms underlying plant responses to drought and salt stresses and their interactions are still not fully understood. We performed a meta-analysis to compare the effects of drought, salt, and combined stresses on plant physiological, biochemical, morphological and growth traits, analyze the different responses of C3 and C4 plants, as well as halophytes and non-halophytes, and identify the interactive effects on plants. There were numerous similarities in plant responses to drought, salt, and combined stresses. C4 plants had a more effective antioxidant defense system, and could better maintain above-ground growth. Halophytes could better maintain photosynthetic rate (Pn) and relative water content (RWC), and reduce growth as an adaptation strategy. The responses of most traits (Pn, RWC, chlorophyll content, soluble sugar content, H2O2 content, plant dry weight, etc.) to combined stress were less-than-additive, indicating cross-resistance rather than cross-sensitivity of plants to drought and salt stresses. These results are important to improve our understanding of drought and salt cross-resistance mechanisms and further induce resistance or screen-resistant varieties under stress combination.

[Effect of changes in posterior tibial slope on the mid-term clinical outcomes of Oxford unicompartmental knee arthroplasty]

Objective: To investigate the impact of changes in the posterior tibial slope (PTS) in Oxford unicompartmental knee arthroplasty (OUKA) on the mid-term clinical outcomes of postoperative patients. Methods: This study was a follow-up study. The data of 135 patients (150 knees) who underwent OUKA at the China-Japan Friendship Hospital from January 2012 to January 2013 were analyzed retrospectively. The patients were followed-up for at least ten years. According to the changes in PTS of the medial tibial plateau before and after surgery, patients were divided into three groups: group A (PTS decreased by more than 5°), group B (PTS changed by 5° or less), and group C (PTS increased by more than 5°). The Knee Society Clinical Score (KSS-C), Knee Society Functional Score (KSS-F), Oxford Knee Score (OKS), Forgotten Joint Score (FJS), and knee range of motion (ROM) among the three groups were compared at the last follow-up. Results: Prior to the final follow-up assessment, six patients expired, and an additional nine patients were lost to follow-up. A total of 120 patients (135 knees) were enrolled in this study (30 males and 90 females). The mean age was (66.29±8.62) years, and the follow-up time was (10.54±0.72) years. Group A consisted of 32 patients (34 knees), group B comprised 77 patients (90 knees), and group C included 11 patients (11 knees). One knee in group A suffered prosthesis loosening, and two knees in group C experienced postoperative bearing dislocation, one knee encountered bearing fragmentation. The incidence of postoperative complications differed significantly among the three groups (P<0.05). The preoperative OKS was (33.91±6.59) points, KSS-F was (43.46±8.99) points, KSS-C was (41.05±5.70) points and ROM was 115.23°±13.53°; after the surgery, they changed to (18.82±7.01) points, (81.51±7.34) points, (82.64±7.94) points, and 119.07°±8.62°, respectively, and all the differences were statistically significant (all P<0.001). In terms of postoperative outcomes, group A had an OKS of (21.44±8.46) points and a FJS of (63.83±11.40) points, group B had an OKS of (17.07±5.81) points and a FJS of (70.49±12.45) points, group C had an OKS of (25.09±5.07) points and a FJS score of (59.48±10.09) points; the differences among the three groups were all statistically significant (all P<0.05), but there were no significant differences in the postoperative KSS scores and ROM among the three groups (all P>0.05). Conclusions: After OUKA, better mid-term clinical outcomes are achieved when ΔPTS is<5°. Although the recommended central value for PTS in OUKA is 7° according to Oxford, it should be individualized, and it is recommended to consider the preoperative angle, with a change of less than 5° before and after surgery.

Response of soil respiration and carbon budget to irrigation quantity/quality and biochar addition in a mulched maize field under drip irrigation

BACKGROUND

Biochar addition strongly alters net carbon (C) balance in agroecosystems. However, the effects of biochar addition on net C balance of maize field under various irrigation water quantities and qualities remains unclear. Thus, a field experiment combining two irrigation levels of full (W1) and deficit irrigation (W2 = 1/2 W1), two water salinity levels of fresh (S0, 0.71 g L-1 ) and brackish water (S1, 4 g L-1 ), and two biochar addition rates of 0 t ha-1 (B0) and 60 t ha-1 (B1) was conducted to investigate soil carbon dioxide (CO2 ) emissions, maize C sequestration and C budget.

RESULTS

Compared with W1, W2 reduced average cumulative CO2 emissions by 6.5% and 19.9% for 2020 and 2021, respectively. The average cumulative CO2 emissions under W1S1 treatments were 5.4% and 22.3% lower than W1S0 for 2020 and 2021, respectively, whereas W2S0 and W2S1 had similar cumulative CO2 emissions in both years. Biochar addition significantly increased cumulative CO2 emissions by 17.8-23.5% for all water and salt treatments in 2020, and reduced average cumulative CO2 emissions by 11.9% for W1 but enhanced it by 8.0% for W2 in 2021. Except for W2S1, biochar addition effectively increased total maize C sequestration by 6.9-14.8% for the other three treatments through ameliorating water and salt stress over the 2 years. Compared with W1S0, W1S1 did not affect net C sequestration, but W2 treatments significantly decreased it. Biochar addition increased net C sequestration by 39.47-43.65 t C ha-1 for four water and salt treatments for the 2 years.

CONCLUSION

These findings demonstrate that biochar addition is an effective strategy to increase both crop C sequestration and soil C storage under suitable water-saving irrigation methods in arid regions with limited freshwater resources. © 2023 Society of Chemical Industry.

Elevated CO2 concentration increases maize growth under water deficit or soil salinity but with a higher risk of hydraulic failure

Climate change presents a challenge for plants to acclimate their water relations under changing environmental conditions, and may increase the risks of hydraulic failure under stress. In this study, maize plants were acclimated to two different CO2 concentrations ([CO2]; 400 ppm and 700 ppm) while under either water stress (WS) or soil salinity (SS) treatments, and their growth and hydraulic traits were examined in detail. Both WS and SS inhibited growth and had significant impacts on hydraulic traits. In particular, the water potential at 50% loss of stem hydraulic conductance (P50) decreased by 1 MPa in both treatments at 400 ppm. When subjected to elevated [CO2], the plants under both WS and SS showed improved growth by 7-23%. Elevated [CO2] also significantly increased xylem vulnerability (measured as loss of conductivity with decreasing xylem pressure), resulting in smaller hydraulic safety margins. According to the plant desiccation model, the critical desiccation degree (time×vapor pressure deficit) that the plants could tolerate under drought was reduced by 43-64% under elevated [CO2]. In addition, sensitivity analysis showed that P50 was the most important trait in determining the critical desiccation degree. Thus, our results demonstrated that whilst elevated [CO2] benefited plant growth under WS or SS, it also interfered with hydraulic acclimation, thereby potentially placing the plants at a higher risk of hydraulic failure and increased mortality.

Salinity-specific stomatal conductance model parameters are reduced by stomatal saturation conductance and area via leaf nitrogen

Modeling stomatal behavior is necessary for accurate stomatal simulation and predicting the terrestrial water‑carbon cycle. Although the Ball-Berry and Medlyn stomatal conductance (g_s) models have been widely used, variations and the drivers of their key slope parameters (m and g₁) remain poorly understood under salinity stress. We measured leaf gas exchange, physiological and biochemical traits, soil water content and electrical conductivity of saturation extract (EC_e), and fitted slope parameters of two genotypes of maize growing in two water and two salinity levels. We found m was different between the genotypes, but no difference in g₁. Salinity stress reduced m and g₁, saturated stomatal conductance (g_sat), the fraction of leaf epidermis area allocation to stomata (f_s), and leaf nitrogen (N) content, and increased EC_e, but no marked decrease in slope parameters under drought. Both m and g₁ were positively correlated with g_sat, f_s, and leaf N content, and negatively correlated with EC_e in the same fashion among the two genotypes. Salinity stress altered m and g₁ by modulating g_sat and f_s via leaf N content. The prediction accuracy of g_s was improved using salinity-specific slope parameters, with root mean square error (RMSE) being decreased from 0.056 to 0.046 and 0.066 to 0.025 mol m^-2 s^-1 for the Ball-Berry and Medlyn models, respectively. This study provides a modeling approach to improving the simulation of stomatal conductance under salinity.

Combination of suitable planting density and nitrogen rate for high yield maize and their source-sink relationship in Northwest China

BACKGROUND

Increasing crop yield per unit area by increasing planting density is essential to ensure food security. However, the optimal combination of planting density and nitrogen (N) application for high-yielding maize and its source-sink characteristics need to be more clearly understood.

RESULTS

A 2-year field experiment was conducted combining three planting densities (D1: 70 000 plants ha^-1 ; D2: 100 000 plants ha^-1 ; D3: 130 000 plants ha^-1 ) and three nitrogen rates (N1: 150 kg hm^-2 ; N2: 350 kg hm^-2 ; N3: 450 kg hm^-2 ). The results showed that increasing planting density significantly increased leaf area index and grain yield but negatively affected ear traits. The Richards model was used to fit the dynamic changes of dry matter accumulation of maize under different treatments, and the fitting results were good. Increasing planting density increased population yield while limiting the development of individual plants, bringing the period of rapid dry matter accumulation to an early end and accelerating leaf senescence. An appropriate nitrogen rate could prolong the period of rapid accumulation of dry matter in maize, and increase the 100-kernel weight. Increasing planting density enhanced post-silking dry matter accumulation to a lesser extent, and the source-sink relationship of the maize population gradually developed from sink limitation to source limitation with increasing planting density.

CONCLUSION

The decrease in yield due to the insufficient source strength to meet the sink demand at too high densities was the reason that limited further improvement of the optimal planting density. An appropriate nitrogen rate facilitated the realization of yield potential at high density. © 2023 Society of Chemical Industry.

Modes and Mechanisms of Pacific Decadal-Scale Variability

The modes of Pacific decadal-scale variability (PDV), traditionally defined as statistical patterns of variance, reflect to first order the ocean's integration (i.e., reddening) of atmospheric forcing that arises from both a shift and a change in strength of the climatological (time-mean) atmospheric circulation. While these patterns concisely describe PDV, they do not distinguish among the key dynamical processes driving the evolution of PDV anomalies, including atmospheric and ocean teleconnections and coupled feedbacks with similar spatial structures that operate on different timescales. In this review, we synthesize past analysis using an empirical dynamical model constructed from monthly ocean surface anomalies drawn from several reanalysis products, showing that the PDV modes of variance result from two fundamental low-frequency dynamical eigenmodes: the North Pacific-central Pacific (NP-CP) and Kuroshio-Oyashio Extension (KOE) modes. Both eigenmodes highlight how two-way tropical-extratropical teleconnection dynamics are the primary mechanisms energizing and synchronizing the basin-scale footprint of PDV. While the NP-CP mode captures interannual- to decadal-scale variability, the KOE mode is linked to the basin-scale expression of PDV on decadal to multidecadal timescales, including contributions from the South Pacific.

The trade-offs between resistance and resilience of forage stay robust with varied growth potentials under different soil water and salt stress

Water shortage and soil salinization are important factors restricting crop production worldwide. To conduct accurate yield prediction and reasonable crop layout, more attention should be paid to the performances of crop resistance and resilience under water and salt stress and their trade-off relationships. Here, we set different water (full irrigation, W0; moderate deficit irrigation, W1; and severe deficit irrigation, W2) and salt (S0, S1, S2, S3, S4, S5, and S6, representing 0 ‰, 1 ‰, 2 ‰, 3 ‰, 4 ‰, 5 ‰, and 6 ‰ salt in soil) treatments. Together with relevant studies, we analyzed the performances of forage resistance (Rt) and resilience (Rs) and their relationships under varied water and salt stress. The results indicated that logarithmic Rt (lg(Rt), the same as lg(Rs)) and the distribution of lg(Rs) were affected by water and salt stress, however, the relationships of lg(Rs)-lg(Rt) stayed stable with the constant slopes (k) and declined intercepts (m) as stress intensified. The physiological mechanisms and trade-offs for fixed species remained robust while the growth potentials varied under stress, which were closely related to stomatal regulations. Forage with larger |k| was suitable for fully irrigated regions to achieve higher yields, while regions with detrimental water and salt conditions should select cultivars with smaller |k| to ensure production. This study laid the groundwork for the estimation of the perennial forage adaptation and stability, and the method of long-term yield prediction and cultivar management under soil water and salt stress.

Plasticity in stomatal behaviour across a gradient of water supply is consistent among field-grown maize inbred lines with varying stomatal patterning

Stomata regulate leaf CO₂ assimilation (A) and water loss. The Ball-Berry and Medlyn models predict stomatal conductance (g_s ) with a slope parameter (m or g₁ ) that reflects the sensitivity of g_s to A, atmospheric CO₂  and humidity, and is inversely related to water use efficiency (WUE). This study addressed knowledge gaps about what the values of m and g₁ are in C₄ crops under field conditions, as well as how they vary among genotypes and with drought stress. Four inbred maize genotypes were unexpectedly consistent in how m and g₁ decreased as water supply decreased. This was despite genotypic variation in stomatal patterning, A and g_s . m and g₁ were strongly correlated with soil water content, moderately correlated with predawn leaf water potential (Ψ_pd ), but not correlated with midday leaf water potential (Ψ_md ). This implied that m and g₁ respond to long-term water supply more than short-term drought stress. The conserved nature of m and g₁ across anatomically diverse genotypes and water supplies suggests there is flexibility in structure-function relationships underpinning WUE. This evidence can guide the simulation of maize g_s across a range of water supply in the primary maize growing region and inform efforts to improve WUE.

Mild water and salt stress improve water use efficiency by decreasing stomatal conductance via osmotic adjustment in field maize

Water and salt stress often occur simultaneously in heavily irrigated arid agricultural areas, yet they are usually studied in isolation. To understand the physiological bases of water use efficiency (WUE) of field-grown maize (Zea mays) at multi-scales under combined water and salt stress, we investigated the joint effects of water and salt stress on physiology, growth, yield, and WUE of two genotypes (XY335 and ZD958). We measured leaf stomatal conductance (g_s), net photosynthesis rate (A) and hydraulic traits, whole-plant growth and water use (ET), and final biomass and grain yield. Leaf osmotic adjustment was a key trait of the physiological differences between XY335 and ZD958 under water and salt stress. Although the responses of the two genotypes were different, mild water and salt stress improved intrinsic water use efficiency (iWUE = A/g_s) by (i) decreasing g_svia increasing osmotic adjustment and hydraulic resistance, and (ii) declining A via increasing stomatal limitations rather than reducing photosynthetic capacity. Joint water and salt stress had a synergistic effect on reproductive growth and grain formation of maize. Mild water and salt stress reduced ET, stabilized grain yield, and improved grain WUE via declining g_s, maintaining photosynthetic capacity, and improving harvest index. Collectively, our study provides a novel insight into the physiological mechanisms of WUE and demonstrates an approach for the efficient management of water and salt by using a growth stage-based deficit irrigation strategy or/and selecting genotypes with strong osmotic adjustment capacity and high harvest index.

The influence of CYP2R1 polymorphisms and gene-obesity interaction with hypertension risk in a Chinese rural population

BACKGROUND AND AIMS

Several studies have reported that variants in CYP2R1 have been linked with an increased risk of hypertension. However, the interaction between CYP2R1 variants and environmental factors on the susceptibility of hypertension remained unclear. Therefore, this study evaluated the influence of CYP2R1 polymorphisms on hypertension susceptibility, and explored the interaction effect of CYP2R1 variations and obesity on the disease.

METHODS AND RESULTS

We included 766 incident hypertension cases matched with non-hypertension controls in a 1:1 ratio by sex, age (within 3 years). Two loci in CYP2R1 gene (rs10766197 and rs12794714) were genotyped by TaqMan probe assays. The concentration of 25-hydroxyvitamin-D was determined by human enzyme-linked immunosorbent assay (ELISA) kits. The associations of CYP2R1 polymorphisms and risks of vitamin D deficiency (VDD) were analyzed by logistic regression. Multifactor dimensionality reduction (MDR) was used to analyze the gene-environment interaction. Multiple logistic regression was used to examine the effect of CYP2R1 gene variations, and the interaction between CYP2R1 variation and obesity on hypertension susceptibility. The results showed that rs10766197 (GG vs. AA) and rs12794714 (GG vs. AA) polymorphisms were both associated with an increased risk of VDD (OR = 1.49, 95% confidence interval (CI) = 1.08-2.05 and OR = 1.63, 95% CI = 1.19-2.25, respectively), after adjustment for potential risk factors. We also found that rs12794714 polymorphism was significantly associated with elevated risk of hypertension under the dominant model (OR = 1.26, 95% CI = 1.01-1.56). In addition, the interactions between rs12794714 with both general obesity (OR = 3.93, 95% CI = 2.72-5.68) and central obesity (OR = 3.22, 95% CI = 2.29-4.52) have significant effects on hypertension susceptibility.

CONCLUSIONS

The study provided further evidence that CYP2R1 variation was associated with a higher risk of hypertension in Chinese rural population. The interaction between CYP2R1 rs12794714 and obesity may increase the risk of hypertension.

Stomatal conductance of tomato leaves is regulated by both abscisic acid and leaf water potential under combined water and salt stress

Stomatal conductance (g_s ) affects water use efficiency (WUE) through coordinating photosynthesis and transpiration and is regulated by chemical and/or hydraulic signals. However, the regulation mechanism of g_s of tomato leaves has not been fully explored under combined water and salt stress. Here, we set up four salt treatments and two water treatments in a climate greenhouse and measured stomatal morphologies and conductance and other photosynthesis parameters. Water and salt stress reduced stomatal length (SL), width, perimeter, area (a_max ), density (SD), and the maximum stomatal conductance (g_smax ). Water and salt stress had a separate weakening effect on net photosynthetic rate (A) and transpiration rate but interactively reduced g_s . The contents of abscisic acid (ABA) and Na⁺ in tomato leaves increased with the NaCl concentration, while leaf water potential (Ψ_l ) and chlorophyll content decreased. Under full irrigation, g_smax was coordinated by SD and a_max , and g_s by ABA content under salt stress. Under water and salt combined stress, g_smax was affected by a_max , and g_s was coordinated with ABA and Ψ_l . The decrease of A was caused by both a reduction of chlorophyll content and g_s under water and salt stress. Intrinsic WUE did not reduce under full irrigation or mild to moderate salt stress but decreased under a combination of water and severe salt stress, indicating that the leaves of the tested tomato cultivar performed better under moderate salt stress. Collectively, these results can provide useful insights for the efficient management of water and salt to adapt to drought and high salt environments.

Measurements of neutral particle energy spectrum on EAST using a time-of-flight low-energy neutral particle analyzer

The neutral particles generated by charge exchange reactions can play an important role in erosion of first wall materials in fusion devices. In order to measure the flux and energy of neutral particles to the first wall, a low-energy neutral particle analyzer (LENPA) based on the time-of-flight method has been developed and successfully applied on the Experimental Advanced Superconducting Tokamak (EAST)' to measure the neutrals with an energy of 20-3000 eV. The LENPA works in the counting mode, and the signal of photons is used as the reference for the flight time of neutrals. The energy spectrum of low-energy neutral particles on EAST has been obtained for the first time. The new diagnostics can help in understanding the neutral particle generation and deposition on the first wall materials in tokamaks under different plasma conditions.

A large-scale genome-wide association analysis reveals QTL and candidate genes for intramuscular fat content in Duroc pigs

This study aimed at identifying genomic regions and genes associated with intramuscular fat content (IMF) in Duroc pigs using a weighted single-step GWAS. Data from 3912 pigs, of which 3770 animals were genotyped with GeneSeek Porcine 50K Bead chip, were used for the association analysis. We identified 19 genomic regions that each explained >1% of the additive genetic variance associated with IMF. Notably, a consistent QTL on SSC7 (117.42-117.92 Mb) was confirmed, explaining 3.70% of the additive genetic variance, and two genes, BDKRB2 and ATG2B, were highlighted as promising candidates for IMF. Two QTL (SSC7, 94.19-94.64 Mb; SSC14, 123.25-123.75 Mb), which harbored MED6 and MAP3K9 genes and TCF7L2 gene respectively, were newly identified as associated with IMF. In conclusion, we identified a consistent QTL and additional genomic regions and genes that contributed to the genetic variance of IMF using a large-scale sample size of genotyped pigs and genealogical information.

Development of machine learning models to predict response after cardiac resynchronization therapy

Background

There have been few practical and precise tools to predict response after cardiac resynchronisation therapy (CRT).

Purpose

We intend to develop predictive models using machine learning (ML) approaches and easily available features prior to implantation.

Methods

The baseline features of 596 patients receiving CRT were retrospectively collected. Nine predictive models were established, including logistic regression (LR), Elastic Net (EN), lasso regression, ridge regression (Ridge), neural network, support vector machine (SVM), random forest, XGBoost and k-nearest neighbor. Sensitivity, specificity, precision, accuracy, F1, area under receiver operating characteristic curve (AU-ROC) and average precision of each model were evaluated, and AU-ROC was compared between each pair of ML models and further between ML models and the latest guidelines.

Results

Sensitivity was highest with SVM by 0.69, and specificity was highest with LR by 0.81. The models EN and Ridge showed the highest overall predictive power with an average AU-ROC of 0.77. Specifically, the Ridge model provided significant higher AU-ROC than any other model (all P&lt;0.05). All ML models showed significant higher AU-ROC than those derived from the latest guidelines (all P&lt;0.05). Additionally, the effect size analysis identified LBBB, LVESD, and history of PCI as the most crucial predictive features.

Conclusion

ML algorithms produced efficient predictive models for evaluation of response after CRT with features prior to implantation. Tools developed accordingly might improve selection of CRT candidates and reduce rate of non-response in the future.

ROC and PR curves of predictive models

Funding Acknowledgement

Type of funding source: None

Development of a quartz crystal microbalance diagnostic for measuring material erosion and deposition on the first wall in EAST

A quartz crystal microbalance (QMB) diagnostic system has been established in Experimental Advanced Superconducting Tokamak (EAST) for real-time and in situ measurements of erosion and deposition rates of plasma-facing materials at the first wall. A ∼70 nm aluminum (Al) film has been coated on the QMB crystal surface to measure the erosion rate by charge exchange neutral particles. Dual sensors of the QMB system have been used with a closed sensor for reference. The stability and light sensitivity of the QMB system have been tested in the lab, demonstrating its feasibility on the application of EAST experiments. The QMB system with cooling water has been successfully applied in the 2018 EAST campaign. The net erosion thickness measured by the QMB has been well validated by thickness measurements using the Rutherford backscattering spectrometry. The developed QMB systems can help us to understand the physics processes of material erosion and deposition at main chamber walls for long pulse operations in EAST.

Elevated [CO2 ] alleviates the impacts of water deficit on xylem anatomy and hydraulic properties of maize stems

Plants can modify xylem anatomy and hydraulic properties to adjust to water status. Elevated [CO₂ ] can increase plant water potential via reduced stomatal conductance and water loss. This raises the question of whether elevated [CO₂ ], which thus improves plant water status, will reduce the impacts of soil water deficit on xylem anatomy and hydraulic properties of plants. To analyse the impacts of water and [CO₂ ] on maize stem xylem anatomy and hydraulic properties, we exposed potted maize plants to varying [CO₂ ] levels (400, 700, 900, and 1,200 ppm) and water levels (full irrigation and deficit irrigation). Results showed that at current [CO₂ ], vessel diameter, vessel roundness, stem cross-section area, specific hydraulic conductivity, and vulnerability to embolism decreased under deficit irrigation; yet, these impacts of deficit irrigation were reduced at elevated [CO₂ ]. Across all treatments, midday stem water potential was tightly correlated with xylem traits and displayed similar responses. A distinct trade-off between efficiency and safety in stem xylem water transportation in response to water deficit was observed at current [CO₂ ] but not observed at elevated [CO₂ ]. The results of this study enhance our knowledge of plant hydraulic acclimation under future climate environments and provide insights into trade-offs in xylem structure and function.

Semen quality pattern and age threshold: a retrospective cross-sectional study of 71,623 infertile men in China, between 2011 and 2017

BACKGROUND

The aim of this study was to provide information on the semen quality pattern of infertile men and age thresholds for semen parameters in China.

METHODS

This was a retrospective cross-sectional study investigating 71,623 infertile men from the Reproductive and Genetic Hospital of CITIC Xiangya in Hunan, China, from 2011 to 2017. The Kruskal-Wallis test, Mann-Kendall test, linear regression model and joinpoint regression were used.

RESULTS

Although erratic changes were observed in the median semen parameters (sperm concentration 40.1-52.1 × 10⁶/ml, total sperm count 117.8-153.1 × 10⁶, sperm progressive motility 33.4-38.1%) during the 7 years of observation, no significant decrease in semen quality was found, and 47.88% of infertile men showed normal semen parameters according to the World Health Organization (WHO) criteria. According to the joinpoint regression analysis, sperm progressive motility appeared to decrease earlier than the sperm concentration and total sperm count (at 28, 58, and 42 years of age, respectively).

CONCLUSIONS

There is no evidence of a deterioration in semen quality among infertile men in Hunan, China. Semen parameters decreased with increasing age, with turning points noted at different ages. Semen parameters are not absolute evidence for the assessment of male fertility potential. Therefore, we believe that, among semen parameters, the sperm concentration is the best predictor of fertility for ART, followed by motility. Decreased sperm motility may affect natural pregnancy, but it is not necessary for successful IVF.

Effects of T cell subsets with different proportions on renal function and blood lipids in patients with preeclampsia

This study aimed to investigate the effect of T cell subsets with different proportions on renal function and blood lipids in patients with preeclampsia (PE). Ninety pregnant women were included in this experiment and classified into 3 groups: group A (30 with severe PE), group B (30 with mild PE) and group C (30 healthy pregnant women). Clinical characteristics were examined. The ratio of T cell subsets in the three groups was detected by flow cytometry. The relationship between PE and T cell subsets was determined. The results showed that no significant difference was found in age or gestational age (P>0.05). The number of CD4+ T cells (CD4 is mainly expressed in helper T cells, referred to as TH) in group A increased significantly compared with group B and group C (P less than 0.05), while the number of CD8+ T cells (CD8+ T cell, also known as cytotoxic T cell (CTL) in group A decreased noticeably in comparison to group C (P less than 0.05). The ratio of CD4+ cell number to CD8+ cell number (TH/CTL) in group A was elevated significantly compared with group B and group C (P less than 0.05). The uric acid (UA) concentration of group A was noticeably elevated compared to group C (P less than 0.05), which differed insignificantly between group B and C (P>0.05). Glomerular filtration rate (GFR) of group A was obviously impaired in comparison to group B and group C (P less than 0.05), which differed insignificantly between group B and C (P>0.05). Total cholesterol (TC) concentrations in group A, C and B were examined. TC concentrations in the former two groups were slightly higher compared to the latter (P less than 0.05), and those in the former two groups were also higher than the normal range (P less than 0.05). Mean triglyceride (TG) concentrations in all 3 groups were above the normal range, and those in group A and B were significantly higher compared to group C (P less than 0.05). TG concentrations differed insignificantly between group B and C (P>0.05). Serum TG, UA and TC in PE patients were positively related to TH/CTL (P less than 0.05). In conclusion, PE is related to T cell subsets, and T cell subsets are closely related to kidney injury and dyslipidemia.

Development of a time-of-flight low-energy neutral particle analyzer for EAST tokamak

To understand the erosion effect of neutral particles on the first wall, a low energy neutral particle analyzer (LENPA), based on the time-of-flight method, has been developed for the Experimental Advanced Superconducting Tokamak (EAST). The LENPA to be installed in the EAST mid-plane mainly consists of a chopper sub-system, a 3 m long flight tube, two sets of detector assemblies, and data acquisition and processing, vacuum, power supply, and control sub-systems. The neutral outflux is gated in bunches of 1 μs time scale by a slotted rotating disc which is driven by a vacuum compatible motor modified from a turbomolecular pump. A He-Ne laser beam is projected through the disc slit to record the instants of chopper slits opening with an avalanche photodiode module. An on-axis electron multiplier detects chopped neutrals, and a central perforated Cu-Be plate is employed to channel the emitted secondary electrons into an off-axis electron multiplier. The radiation peaks of on-axis electron multiplier caused by UV photons projected through the central hole of the Cu-Be plate provide an alternative way to record the chopper slits' opening time. With an additional 4 TB fast memory card, 1 GS/s sampling rate has been realized by using a GaGe acquisition card continuously. The LENPA data from the EAST together with neutral particle material erosion experiments will be used to benchmark the simulation results for better predictions on future fusion reactors, such as ITER and China Fusion Engineering Test Reactor (CFETR).

Gamma-glutamyl transpeptidase to cholinesterase and platelet ratio in predicting significant liver fibrosis and cirrhosis of chronic hepatitis B

OBJECTIVES

To evaluate the performance of a new mathematical model γ-glutamyl transpeptidase to cholinesterase and platelet ratio (GCPR) versus γ-glutamyl transpeptidase to platelet ratio (GPR) in predicting significant fibrosis and cirrhosis of chronic hepatitis B.

METHODS

A complete cohort of 2343 patients was divided into early and late cohort depending on the time of liver biopsy. With reference to the Scheuer standard, liver pathologic stage 2 or higher and stage 4 or higher were defined as significant fibrosis and cirrhosis, respectively. Receiver operating characteristic (ROC) curve was used to evaluate the performance of investigated models.

RESULTS

In the early cohort, the areas under ROC curves (AUROCs) of GCPR in predicting significant fibrosis of hepatitis B e antigen (HBeAg)-positive and HBeAg-negative patients (0.782 and 0.775) were both significantly greater than those of GPR (0.748 and 0.747) (Z = 8.198 and Z = 6.023, both p <0.0001); the AUROCs of GCPR in predicting cirrhosis of HBeAg-positive and HBeAg-negative patients (0.842 and 0.861) were both significantly greater than those of GPR (0.802 and 0.823) (Z = 6.686 and Z = 6.116, both p <0.0001). In early, late and complete cohorts, using a single cutoff of GCPR > 0.080, the specificities of GCPR in predicting significant fibrosis of HBeAg-positive patients were 83.3%, 88.2% and 85.0% and of HBeAg-negative patients were 87.6%, 87.4% and 87.6%, respectively; and the sensitivities of GCPR in predicting cirrhosis of HBeAg-positive patients were 81.9%, 88.7% and 84.2% and of HBeAg-negative patients were 83.1%, 82.1% and 82.7%, respectively.

CONCLUSIONS

GCPR has higher performance than GPR in predicting significant fibrosis and cirrhosis of chronic hepatitis B.

[Association of Crohn's disease with aryl hydrocarbon receptor gene polymorphisms and haplotypes]

Objective: To explore the relationship of Crohn's disease (CD) susceptibility to aryl hydrocarbon receptor (AhR) polymorphisms and haplotypes in Han population in Wenzhou city, China. Methods: A total of 310 CD patients and 573 age- and sex-matched healthy controls were enrolled in our study. Three single nucleotide polymorphisms (SNPs) of AhR(rs10249788,rs2158041,rs2066853) were determined by the improved multiple ligase detection reaction technique. Unconditional logistic regression analyses was applied to analyze the allelic and genotypic differences of each SNP between CD patients and controls, as well as their influence on the clinicopathologic characteristics in CD patients. Analyses of linkage disequilibrium and haplotype were performed by Haploview 4.2 software in all study subjects. Results: Compared with the controls, the variant allele (T) and genotype (CT+TT) of (rs2158041) were evidently decreased among CD patients (19.52% vs. 25.04%, P=0.009; 34.19% vs. 44.68%, P=0.003). According to "the Montreal Classification Standards" , CD patients were divided into different subgroups. The variant allele (T) and genotype (CT+TT) of (rs2158041) were significantly lower in patients with terminal ileum CD than in controls (16.79% vs. 25.04%, P=0.005; 28.24% vs. 44.68%, P=0.001). Similar conclusions were also drawn in patients with constricting disease when compared with the controls (15.20% vs. 25.04%, P=0.003; 28.43% vs. 44.68%, P=0.003). The three SNPs above were shown to be in a linkage disequilibrium. Compared with the controls respectively, the frequency of haplotype (CCG) was increased in CD patients (44.73% vs. 39.60%, P=0.039), whereas that of haplotype (CTG) was decreased (18.02% vs. 22.78%, P=0.047). Conclusions: AhR (rs2158041) variation might influence the risk as well as the location and behavior of CD. The haplotype (CCG) possibly increase the risk of CD development, whereas haplotype (CTG) might decrease it.

[Association of ulcerative colitis with fork head/winged helix transcription factor-3 gene polymorphisms in Chinese patients]

Objective: To investigate the association of ulcerative colitis (UC) with fork head/winged helix transcription factor-3 (Foxp3) polymorphisms in Han population in Zhejiang province, China. Methods: A total of 381 UC patients and 490 healthy controls were enrolled in this study.The four single nucleotide polymorphisms (SNPs) of Foxp3 (rs3761547, rs2232365, rs2294021, rs3761548) were examined by SNaPshot.The analyses of linkage disequilibrium (LD) and haplotype were also performed in all study subjects. Results: When male and female UC patients were compared with their corresponding controls respectively, the alleles and genotypes of the four SNPs were not statistically different (all P>0.05). According to severity and location of the disease, the UC patients were divided into different subgroups. The alleles (C, G, A) of (rs2232365, rs2294021, rs3761548) were more frequent in male patients with severe UC than in the male controls (69.6% vs 34.3%, P=0.001; 69.6% vs 34.3%, P=0.001; 39.1% vs 14.4%, P=0.002, respectively). As compared with the female controls, the alleles (C, G, A) and genotypes (TC+ CC, AG+ GG, CA+ AA) of (rs2232365, rs2294021, rs3761548) were significantly increased in the female patients with severe UC (51.9% vs 38.0%, 63.5% vs 39.2%, 53.8% vs 21.4%, 80.8% vs 57.7%, 84.6% vs 58.4%, 76.9% vs 34.7%, all P<0.05). The four SNPs above were shown to be in a strong LD both in male and in female subjects.When male and female UC patients were compared with their corresponding controls respectively, nevertheless, each haplotype frequency was not statistically different (all P>0.05). Conclusions:Foxp3 (rs2232365, rs2294021, rs3761548) variations might engender the increased risk of severe UC in Chinese Han patients.

[Research advances in the role of interleukin-21 in chronic hepatitis B virus infection]

Interleukin-21 (IL-21) is a cytokine mainly secreted by activated CD4+ T cells and natural killer T cells and has multiple effects. It is involved in innate and adaptive immune responses. Recent studies have shown that IL-21 can promote functional activation of various immune cells in the process of hepatitis B virus (HBV) infection, and the gene polymorphisms of IL-21 is associated with the susceptibility to HBV. In addition, the expression of IL-21 is closely associated with HV genotype, HBV clearance, HBeAg seroconversion, HBV-related liver cirrhosis, liver failure, liver cancer, and autoimmune disease. This article reviews the research advances in clinical trials with reference to the aspects above.

The formation of H bubbles at small-angle tilt grain boundaries in W films

The accumulation of H at the small-angle tilt grain boundary (GB) in the W(001) surface is investigated, on the basis of the first-principles calculations. By exploring the solution and diffusion behaviors of H at the GB, we find that the small-angle GB can capture the H atoms nearby, serving as a nucleation site of H bubbles. With the increasing number of trapped H atoms, the GB expands gradually, and the GBs can be unripped with an areal density of H up to 5.0 × 10¹⁵ H atoms per cm², leading to the formation of H bubbles. Moreover, H₂ molecules are observed, when the areal density of H atoms in GB is over 6.6 × 10¹⁵ atoms per cm². According to our calculations, we propose a possible formation mechanism of H bubbles observed in the experiment, which is valuable for improving the service performance of W as a plasma-facing material in nuclear fusion reactors.

Effect of iguratimod and methotrexate on RANKL and OPG expression in serum and IL-1β-induced fibroblast-like synoviocytes from patients with rheumatoid arthritis

The receptor activator of nuclear factor κB ligand (RANKL)/receptor activator of nuclear factor κB (RANK)/osteoprotegerin (OPG) system plays a key role in rheumatoid arthritis (RA)-associated bone erosion. The upregulation of the RANKL/OPG ratio promotes bone erosion. The objective of this study is to explore the effects of iguratimod, a small-molecule disease-modifying antirheumatic drug (DMARD), alone or in combination with methotrexate (MTX), on RANKL and OPG expression in RA. We performed an enzyme-linked immunosorbent assay (ELISA) to investigate the modulatory effects of iguratimod, MTX, or their combination on serum RANKL and OPG levels of patients with RA before and after treatment for 12 and 24 weeks. Furthermore, fibroblast-like synoviocytes (FLS) from patients with RA were interleukin (IL)-1β-stimulated and then treated with different concentrations of iguratimod, MTX, or both, and RANKL and OPG expressions were investigated by using ELISA, quantitative real-time polymerase chain reaction (qPCR) and western blot analysis. We found that RANKL levels and the RANKL/OPG ratio significantly decreased in both serum and IL-1β-induced RA FLS after treatment. Moreover, combination therapy with iguratimod and MTX showed an even stronger inhibition than each drug alone did. Our results suggest that iguratimod and MTX, especially in combination, efficaciously protected against bone erosion by suppressing the production of RANKL.