[Research progress on the application of time-restricted eating in adult obesity and related metabolic diseases].

The soaring prevalence of obesity and its complications presents a significant health care burden, and there is currently a lack of effective and sustainable treatment methods. Time-restricted eating (TRE) is a specific intermittent fasting (IF) protocol involving consistent fasting and eating periods within a 24-hour cycle. Time-restricted eating can restore robust circadian rhythms and improve metabolic health, providing an emerging dietary strategy for the prevention and treatment of obesity and related metabolic diseases. Previous TRE trials laid the groundwork, and indicate a need for further clinical research including large-scale controlled trials to determine TRE efficacy and the mechanisms by which it may affect humans.

[Consideration on the construction of a special research database for human papillomavirus vaccination in high-risk and special populations].

The application of human papillomavirus (HPV) vaccine in China has accelerated in recent year. Women's and Children's hospitals as well as general hospitals have established HPV vaccination counselling clinic in succession. A large amount of valuable preventive and clinical data have been generated in the evaluation, recommendation, immunization and management of HPV vaccine for high-risk and special populations. This article sorted out the operation process of HPV vaccination counselling clinic, discussed the methods for hospitals to construct a special research database for HPV vaccination in high-risk and special populations under different degrees of informatization. It also provided a reference for the establishment of unified data standards, the formation of available data resources, and the promotion of real world study on HPV vaccination for high-risk and special populations in China.

[Determination of acetylacetone in workplace air by solvent desorption-gas chromatography].

Objective: To establish a method for the determination of acetylacetone in the air of workplace by gas chromatography. Methods: In August 2020, acetylacetone in the air of workplace was collected by silica gel tube, eluted with methanol, separated and detected by gas chromatography with flame ionization detector. The detection limit and precision of the method were also analyzed. Results: The linear range of acetylacetone was 1.95-1950.60 µg/ml with the regression equation of y=0.815x-3.667, and the correlation coefficient was 0.99993. The limit of detection of the method was 0.18 µg/ml and the minimum detection concentration was 0.12 mg/m(3) (collected sample volume was 1.50 L). The within-run precisions were 1.08%-4.11% and the between-run precisions were 1.98%-2.80%. The desorption rates were 99.68%-100.45%. The sealed samples could be kept at least 15 days at room temperature without significant loss. Conclusion: The solvent desorption-gas chromatography method for the determination of acetylacetone has good precision, high sensitivity and simple operation, and is suitable for the determination of acetylacetone in the air of the workplace.

[The method of determination for butyronitrile and isobutyronitrile in the air of workplace by dissolved desorption-gas chromatography].

Objective: To establish a method for the determination of butyronitrile and isobutyronitrile in the air of workplace by gas chromatography. Methods: In March 2020, butyronitrile and isobutyronitrile in the air of workplace was collected by silica gel, eluted with methanol, separated and determined by gas chromatogram with flame ionization detector, the characteristics of determination of nitrile and isobutyronitrile by gas chromatography were analyzed. Results: The limit of detection for butyronitrile and isobutyronitrile was 0.33 µg/ml. The linear range of butyronitrile determined by this method was 1.60-1600.00 µg/ml, y=2.295x-3.480, and the coefficient correlation was 0.99998, and the minimum detection concentration was 0.22 mg/m(3) (collected sample volume was 1.50 L) . The within-run precisions were 2.43%-4.12%, the between-run precisions were 1.72%-3.70%, and the desorption rates were 93.26%-98.41%. The linear range of isobutyronitrile determined by this method was 1.52-1520.00 µg/ml, y=2.208x-0.102, and the coefficient correlation was 0.99998, and the minimum detection concentration was 0.22 mg/m(3) (collected sample volume was 1.50 L) . The within-run precisions were 2.52%-3.22%, the between-run precisions were 1.20%-3.82%, and the desorption rates were 96.85%-102.50%. The sealed samples could be stored at least 10 days at room temperature without significant loss. Conclusion: The method has the advantages of good precision, high sensitivity and simple operation. It is suitable for the simultaneous determination of butyronitrile and isobutyronitrile in the air of workplace.

Modulation of rumen fermentation and microbial community through increasing dietary cation-anion difference in Chinese Holstein dairy cows under heat stress conditions.

AIMS: The effect of increasing dietary cation-anion difference (DCAD) on rumen fermentation and ruminal microbial community in dairy cows under heat stress (HS) conditions were evaluated. METHODS AND RESULTS: This study was performed as a two-period cross-over design during the summer season, with eight lactating dairy cows randomly distributed to either a control DCAD diet (CON: 33·5 mEq/100 g DM) or high DCAD diet (HDCAD: 50·8 mEq/100 g DM). Throughout the present study, the temperature and humidity index (THI; 80·2 ± 4·29) was generally elevated above the threshold (THI = 72) that is reported to cause HS in lactating dairy cows. Rumen liquid samples were collected on 15 and 21 d during each 21 d-period. The absolute concentration of ruminal total volatile fatty acid (TVFA) in HDCAD treatment was significantly (P < 0·05) higher than those in the control, whilst the ruminal pH, NH3 -N, and VFA molar percentages were unaffected through increasing DCAD. Furthermore, the copy numbers of the cellulolytic bacteria Ruminococcus albus and Ruminococcus flavefaciens in rumen fluid significantly (P < 0·05) rose along with the increment of DCAD. Although the Alpha diversity indexes and the bacterial microbiota structure were unaffected, increasing DCAD significantly (P < 0·05) enriched the phylum Fibrobacteres and genus Fibrobacter in the microflora of rumen fluid, whilst the genera Flexilinea and Dubosiella were the most differentially abundant taxa in the control. CONCLUSIONS: Increasing DCAD under HS conditions resulted in a greater concentration of total VFA without affecting rumen bacteria diversity or structure, although the enrichment of some cellulolytic/hemicellulolytic bacteria was observed. SIGNIFICANCE AND IMPACT OF THE STUDY: The present study provides information on the modulation of rumen fermentation and microbial community through the increment of DCAD in Holstein dairy cows under HS conditions.

[Treatment and prevention of bile duct injury in hepatocellular carcinoma after transarterial chemoembolization].

Transarterial chemoembolization is the first choice for patients with advanced stage liver cancer who are not apt for surgical resection. In clinical practice, rare and serious complications occur occasionally, and bile duct injury is one of the complications after transarterial chemoembolization. Therefore, understanding its mechanism and high-risk factors can reduce the occurrence of bile duct injury, and early detection and treatment can significantly improve the prognosis. This article summarizes the clinical research progress of bile duct injury in hepatocellular carcinoma after transarterial chemoembolization.

[Application of a new solid adsorbent tube for the determination of three kinds of epoxy eompounds in air].

Objective: To develop a new solid sorbent tube for simultaneously capturing ethylene oxide (EO) , propylene oxide (PO) and epichlorohydrin (ECH) in air, and establish a complete set of method. Methods: In June 2018, EO, PO and ECH in air were captured by the new solid sorbent tube filled with carbon aerogel adsorbent, desorbed with solution of 5% (V/V) methanol-methylene chloride, separated through capillary chromatographic column, and then analyzed by gas chromatography-flame ionization detector. Results: The linear ranges of EO, PO and ECH were 0.24-960.00, 0.60-2384.00 and 0.12-472.40 mg/L respectively, and the related coefficients were between 0.99995-0.99997. The relative standard deviations (RSD) within the group were 1.66%-4.09%, 1.36%-4.43%, and 1.99%-5.65%, respectively, and the RSD between the group were 2.69%-4.95%, 2.77%-5.30%, and 3.27%-6.67%, respectively. The average desorption efficiencies were 88.25%-94.50%, 98.17%-98.60%, and 97.79%-101.04%, respectively. The samples could be stored at 4 ℃ refrigerator for at least 27 days. Conclusion: The newly developed solid sorbent tube filled with carbon aerogel adsorbent and its complete set of gas chromatography method could be used for sampling and quantitative detection of EO, PO and ECH in workplace air.

[Simultaneous determination of four kinds methyl acrylate compounds in workplace air].

Objective: To develop a solvent desorption-gas chromatography method for simultaneous determination of methyl methacrylate (MMA) , ethyl methacrylate (EMA) , n-propyl methacrylate (PMA) and butyl methacrylate (BMA) in workplace air. Methods: MMA, EMA, PMA and BMA in workplace air were captured by charcoal tubes and desorbed with carbon disulfide, separated through capillary chromatographic column, and then analyzed by gas chromatography-flame ionization detector. Results: The linear ranges of MMA, EMA, PMA and BMA were 0-8 305.00 mg/L, 0-9 080.50 mg/L, 0-8 899.00 mg/L and 0-8 371.00 mg/L respectively, and the related coefficients were between 0.999 96-0.999 98. The relative standard deviations (RSD) within the group were 0.56%-1.71%, 0.45%-1.65%, 0.51%-1.49% and 0.45%-1.50% respectively, and the RSD between the group were 1.14%-2.79%, 0.79%-2.13%, 0.93%-2.30% and 1.09%-2.84% respectively. The average desorption efficiencies were 95.76%-99.58%, 97.82%-102.28%, 98.55%-102.28%and 98.70%-102.40% respectively. The minimum quantification concentrations were 0.12 mg/m(3), 0.10 mg/m(3), 0.07 mg/m(3) and 0.07 mg/m(3) respectively (3.00 L sample) . The samples could be stored at room temperature for at least 7 days. Conclusion: This method could be used for monitoring of MMA, EMA, PMA and BMA in workplace air.

[Effects of calcineurin gene silencing on the remodeling of transient outward potassium current ionic channel in hypertrophic ventricular myocytes from neonatal rats].

Objective: To investigate the effects of calcineurin gene silencing on the remodeling of transient outward potassium current (Ito) ionic channel and action potential duration (APD) in phenylephrine (PE)-induced hypertrophic ventricular myocytes from neonatal rats. Methods: The ventricular myocytes of 1-day-old Sprague-Dawley rats were isolated and cultured for 48 h. RNA interference mediated by adenovirus carrying short hairpin RNA was used to knock down the gene which encodes the beta subtype of calcineurin A subunit (CnAß) and the cells were divided into 4 groups as Ad-null group, Ad-null+ PE group, Ad-CnAßshRNA1(A1) group and A1+ PE group, and then cultured for 48 h. The gene expression of Kv4.2 was assayed by real-time reverse transcriptase-polymerase chain reaction. The protein expressions of CnAß and Kv4.2 were assayed by Western blot test. Whole cell patch clamp technique was used to record Ito and action potential. Results: Treatment of the neonatal rat ventricular myocytes with PE induced the cell hypertrophy, up-regulated the protein expression of CnAß, attenuated the gene and protein expressions of Kv4.2 and the Ito current density, and prolonged APD. Silencing of CnAß in the neonatal rat ventricular myocytes using Ad-CnAßshRNA1 inhibited the aforementioned ability of PE significantly. Conclusion: CnAß gene silencing inhibits the remodeling of transient outward potassium current ionic channel and change of APD in PE-induced hypertrophic ventricular myocytes from neonatal rats.

[Determination of volatile organic compounds in air by portable gas chromatography-mass spectroscopy].

Objective: To investigate the method of portable gas chromatography-mass spectroscopy (GC-MS) for the determination of common volatile organic compounds in air. Methods: The static volumetric method was used, with highly purified nitrogen gas as the diluents gas, to prepare the mixed standard gas of common volatile organic compounds with various mass concentrations. A portable GC-MS handheld probe was used for sampling and measurement, retention time and characteristic ion were used for qualitative analysis, and the full-scan mode was used for quantitative analysis. Results: The correlation coefficient of 12 volatile organic compounds determined by this method was higher than 0.999. The minimum detection mass concentration was 0.02~0.12 mg/m3, and the minimum quantitative mass concentration was 0.07~0.40 mg/m3. The relative standard deviation of precision was 4.10%~12.50%; the relative deviation of acetone, benzene, methylbenzene, and dimethylbenzene was-13.56% , 9.03% , -10.82% , and 8.67% , respectively. Conclusion: Portable GC-MS method can be used for the qualitative analysis and quantification of volatile organic compounds in occupational hazard factors and provide technical supports for identification of occupational hazard factors.

Decreased functional connectivity between the mediodorsal thalamus and default mode network in patients with disorders of consciousness.

BACKGROUND: Interactions between the thalamus and the cortex play an important role in consciousness. The thalamus as a homogenous structure is less strongly connected with the default mode network (DMN) in patients with disorders of consciousness (DOC), but the roles of specific thalamic nuclei are not clear. The purpose of this study was to investigate the functional connectivity between individual thalamic nuclei and the DMN in DOC patients. METHODS: Nine DOC patients and nine age-matched healthy controls were scanned with functional magnetic resonance imaging (fMRI) at resting state. Data-driven independent component analysis and hypothesis-driven region of interest-based correlation analysis were performed. RESULTS: In comparison with healthy controls, DOC patients had significantly decreased functional connectivity between the mediodorsal thalamus and brain areas within the DMN, including the medial prefrontal cortex and posterior cingulate cortex/precuneus. Patients and controls did not show significant differences in functional connectivity in other thalamic nuclei. CONCLUSION: Our results suggest that functional connections between the mediodorsal thalamus and the DMN may play important roles in the pathogenesis of DOC.

Resveratrol induces antioxidant and heat shock protein mRNA expression in response to heat stress in black-boned chickens.

This study investigated the effects of dietary resveratrol at 0, 200, 400, or 600 mg/kg of diet on the performance, immune organ growth index, serum parameters, and expression levels of heat shock protein (Hsp) 27, Hsp70, and Hsp90 mRNA in the bursa of Fabricius, thymus, and spleen of 42-d-old female black-boned chickens exposed to heat stress at 37 ± 2°C for 15 d. The results showed that heat stress reduced daily feed intake and BW gain; decreased serum glutathione (GSH), growth hormone, and insulin-like growth factor-1 levels; and inhibited GSH peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) activities compared with birds subjected to thermo-neutral circumstances. Chickens that were fed diets supplemented with resveratrol exhibited a linear increase in feed intake and BW gain (P < 0.001); serum GSH, growth hormone, and insulin-like growth factor-1 levels (P ≤ 0.01); and GSH-Px, SOD, and CAT activities (P < 0.001) compared with chickens that were fed diets without resveratrol during heat stress. In contrast, serum malonaldehyde concentrations were decreased (P < 0.001) in the chickens fed a resveratrol-supplemented diet. Heat stress also reduced (P < 0.05) the growth index of the bursa of Fabricus and spleen; however, it had no effect on the growth index of the thymus. The growth index of the bursa of Fabricius and spleen increased (P < 0.05) upon heat stress and coincided with an increase in supplemental resveratrol levels. The expression of Hsp27, Hsp70, and Hsp90 mRNA in the bursa of Fabricius and spleen were increased (P < 0.01), but those of Hsp27 and Hsp90 mRNA in thymus were decreased (P < 0.01) under heat stress compared with no heat stress. Resveratrol attenuated the heat stress-induced overexpression of Hsp27, Hsp70, and Hsp90 mRNA in the bursa of Fabricius and spleen and increased the low expression of Hsp27 and Hsp90 mRNA in thymus upon heat stress. The results suggest that supplemental resveratrol improves growth performance and reduces oxidative stress in heat-stressed black-boned chickens by increasing serum growth hormone concentrations and modulating the expression of heat shock genes in organs of the immune system.

Risk factors for the development of cryptogenic stroke and the predictive value of right-to-left shunt in patent foramen ovale.

OBJECTIVE: The purpose of this study was to evaluate the relationship between the right-to-left shunt of the patent foramen ovale and the risk score for paradoxical embolism in cryptogenic stroke, as well as the risk factors for the development of cryptogenic stroke. PATIENTS AND METHODS: A retrospective analysis was performed on 257 patients with cryptogenic stroke who were diagnosed and treated in our hospital from February 2020 to January 2022 as a study group, and 98 patients who were diagnosed and treated at the Department of Neurology in our hospital at the same time and excluded from stroke, were selected as the control group. Transcranial Doppler ultrasound acoustic contrast testing was used to grade right-to-left shunts of patent foramen ovale. Clinical information of individuals who had cryptogenic strokes was examined. The correlation between the right-to-left shunt of patent foramen ovale and the risk score for both cryptogenic stroke and paradoxical embolism was analyzed. The factors affecting the occurrence of cryptogenic stroke were investigated. The correlation between right-to-left shunt and paradoxical embolism risk score was explored. Receiver operator characteristic curve (ROC) analysis was used to evaluate each factor's clinical usefulness in predicting the occurrence of cryptogenic stroke. RESULTS: No difference was observed in the history of hypertension, low-density lipoprotein, C-reactive protein and fibrinogen between the control group and the study group (p<0.05). In the study group with patent foramen ovale, the proportion of patients with grades I and II of the right-to-left shunt of patent foramen ovale was significantly lower than that in the control group, while the percentage of patients with grades III and IV was obviously greater than that in the control group (p<0.05). Right-to-left shunt grade, C-reactive protein, and fibrinogen were independent risk factors for cryptogenic stroke by logistic multivariate regression analysis (p<0.05). With an increase in the right-to-left shunt of the patent foramen ovale, patients' risk scores for paradoxical embolism increased considerably (p<0.05). In patients with cryptogenic stroke, the right-to-left shunt grade of the patent foramen ovale was positively connected with the paradoxical embolism risk score (r=0.331, p<0.001). ROC analysis results showed that the areas under the curves (AUC) of right-to-left shunt grading, C-reactive protein, and fibrinogen were 0.651, 0.871, and 0.779, respectively. The combination of the three indexes had an AUC of 0.908, a sensitivity of 87.90%, a specificity of 82.70%, and a Youden index of 0.706, indicating a high predictive value of the combination. CONCLUSIONS: The right-to-left shunt of patent foramen ovale was an independent risk factor for cryptogenic stroke, which was positively correlated with the paradoxical embolic risk score. Its combination with clinical serologic indexes had a high clinical value for predicting cryptogenic stroke.

[Retrospective study of role of neoadjuvant rectal scores in evaluating the 10-year disease-free survival of patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiotherapy followed by surgery].

Objective: To investigate the correlation between the neoadjuvant rectal (NAR) score and long-term survival in patients with locally advanced rectal cancer who have undergone neoadjuvant chemoradiotherapy. Methods: Clinical and pathological data of 487 patients diagnosed with rectal adenocarcinoma from October 2004 to April 2014 at Sun Yat-sen University Cancer Center who had received neoadjuvant chemoradiotherapy were retrospectively analyzed and the impact of NAR score on prognosis studied. Disease-free-survival (DFS) was calculated by the Kaplan-Meier method and survivals compared using the log-rank test. Cox models were used for univariate and multivariate analyses. Receiver operating characteristic curves were utilized to evaluate the predictive capability of NAR and tumor regression grade scores for the risk of 10-year postoperative recurrence and metastasis. The Delong test was employed to compare the diagnostic performance of the two scores. Results: Of the 487 patients included in the study, 166 were men (34.1%). The median age was 56 years (interquartile range [IQR]: 46-63). All patients completed adequate preoperative chemoradiotherapy and underwent R0 resection.The median interval between the end of chemoradiotherapy and surgery was 51 days (IQR: 44-58). Post-chemoradiotherapy downstaging occurred in 329 patients (67.6%). Tumor regression grades (TRGs) were 1-2 in 246 patients (50.5%) and 3-4 in 241 patients (49.5%). A total of 394 patients (80.9%) received postoperative chemotherapy. NAR scores were <8 in 182 patients (37.4%), 8-16 in 180 (37.0%), and >16 in 125 (25.6%). The median follow-up time was 111.5 months (IQR: 70.7-133.7 months). One hundred and thirteen patients died of rectal cancer, among whom 13 patients developed local recurrence, 88 patients developed distant metastasis, and 12 patients had unknown recurrence patterns. The 10-year DFS and overall survival rate of f the whole group were 68.9% and 71.5% respectively. The 10-year DFS rates for patients with NAR scores <8, 8-16, and >16 were 85.1%, 80.5%, and 66.4%, respectively (P<0.001). Multivariate analyses revealed that the Dixon operation (HR=0.606, 95%CI: 0.408-0.902, P=0.014), and >16 (HR=2.569, 95%CI: 1.559-4.233, P<0.001) were independent predictors of the 10-year DFS of patients with locally advanced rectal cancer (P<0.05 for all). In the entire patient cohort, the AUC of the receiver operating characteristic curve for NAR score predicting 10-year recurrence and metastasis was 0.67 (95%CI: 0.62-0.72), whereas the AUC for TRG score was 0.54 (95%CI: 0.49-0.60). The two scores differed significantly in accuracy (Z=-4.06, P<0.001), the NAR score being a significantly better predictor of risk of 10-year recurrence and metastasis than the TRG score. Conclusion: The NAR score is a reliable predictor of 10-year DFS in patients with locally advanced rectal cancer who have undergone neoadjuvant chemoradiotherapy followed by curative surgery.

Support vector machine-based nomogram predicts postoperative distant metastasis for patients with oesophageal squamous cell carcinoma.

BACKGROUND: We aim to develop effective models for predicting postoperative distant metastasis for oesophageal squamous cell carcinoma (OSCC) for the purpose of guiding tailored therapy. METHODS: We used data from two centres to establish training (n=319) and validation (n=164) cohorts. All patients underwent curative surgical treatment. The clinicopathological features and 23 immunomarkers detected by immunohistochemistry were involved for variable selection. We constructed eight support vector machine (SVM)-based nomograms (SVM1-SVM4 and SVM1'-SVM4'). The nomogram constructed with the training cohort was tested further with the validation cohort. RESULTS: The outcome of the SVM1 model in predicting postoperative distant metastasis was as follows: sensitivity, 44.7%; specificity, 90.9%; positive predictive value, 81.0%; negative predictive value, 65.6%; and overall accuracy, 69.5%. The corresponding outcome of the SVM2 model was as follows: 44.7%, 92.1%, 82.9%, 65.9%, and 70.1%, respectively. The corresponding outcome of the SVM3 model was as follows: 55.3%, 93.2%, 87.5%, 70.7%, and 75.6%, respectively. The SVM4 model was the most effective nomogram in prediction, and the corresponding outcome was as follows: 56.6%, 97.7%, 95.6%, 72.3%, and 78.7%, respectively.Similar results were observed in SVM1', SVM2', SVM3', and SVM4', respectively. CONCLUSION: The SVM-based models integrating clinicopathological features and molecular markers as variables are helpful in selecting the patients of OSCC with high risk of postoperative distant metastasis.

Solar energy harvesting scheme using syringe-like ZnO nanorod arrays for InGaN/GaN multiple quantum well solar cells.

Syringe-like ZnO nanorod arrays (NRAs) synthesized by a hydrothermal method were applied as the light-harvesting layer on InGaN-based multiple quantum well (MQW) solar cells. Theoretical calculations show that the NRAs with an abrupt shrinkage of tip diameter can further suppress surface reflectance in comparison with the flat NRAs. InGaN-based MQW solar cells with the syringe-like NRAs exhibit greatly improved conversion efficiencies by 36%. These results are attributed to the improved flatness of the refractive index profile at the air/device interface, which results in enhanced light trapping effect on the device surface.

n-ZnO/LaAlO3/p-Si heterojunction for visible-blind UV detection.

A visible-blind UV photodetector (PD) using a double heterojunction of n-ZnO/LaAlO3 (LAO)/p-Si was demonstrated. Inserted LAO layers exhibit electrical insulating properties and serve as blocking layers for photoexcited electrons from p-Si to n-ZnO, leading to an enhanced rectification ratio and a visible-blind UV detectivity of the n-ZnO/LAO/p-Si PDs due to the high potential barrier between LAO and p-Si layers (~2.0 eV). These results support the use of n-ZnO/LAO/p-Si PDs in the visible-blind UV PDs in a visible-light environment.

Differentially expressed genes implicated in embryo abortion of mango identified by suppression subtractive hybridization.

Embryo abortion in mango severely damages mango production worldwide. The mechanisms by which the mango embryos abort have long been an intriguing question. We used subtractive suppression hybridization to investigate the differentially expressed genes involved in this process. We generated 2 cDNA libraries from normal seed and aborted seed embryos of mango cultivar 'Jinhuang'. One thousand five hundred and seventy-two high-quality expressed sequence tags (ESTs) were obtained, with 1092 from the normal seed tester library and 480 from the aborted seed tester library. These ESTs were assembled into 783 unigenes, including 147 contigs and 636 singletons in contigs; 297 singletons in gene ontology (GO) indicated coverage of a broad range of GO categories. Seven candidate genes from different categories were selected for semi-quantitative PCR analysis, and their possible functions in embryo abortion are discussed. These data provide new insight into the genetic regulation of embryo abortion in mango and may aid in further identification of novel genes and their functions.

Allelic interaction of F1 pollen sterility loci and abnormal chromosome behaviour caused pollen sterility in intersubspecific autotetraploid rice hybrids.

The intersubspecific hybrids of autotetraploid rice has many features that increase rice yield, but lower seed set is a major hindrance in its utilization. Pollen sterility is one of the most important factors which cause intersubspecific hybrid sterility. The hybrids with greater variation in seed set were used to study how the F(1) pollen sterile loci (S-a, S-b, and S-c) interact with each other and how abnormal chromosome behaviour and allelic interaction of F(1) sterility loci affect pollen fertility and seed set of intersubspecific autotetraploid rice hybrids. The results showed that interaction between pollen sterility loci have significant effects on the pollen fertility of autotetraploid hybrids, and pollen fertility further decreased with an increase in the allelic interaction of F(1) pollen sterility loci. Abnormal ultra-structure and microtubule distribution patterns during pollen mother cell (PMC) meiosis were found in the hybrids with low pollen fertility in interphase and leptotene, suggesting that the effect-time of pollen sterility loci interaction was very early. There were highly significant differences in the number of quadrivalents and bivalents, and in chromosome configuration among all the hybrids, and quadrivalents decreased with an increase in the seed set of autotetraploid hybrids. Many different kinds of chromosomal abnormalities, such as chromosome straggling, chromosome lagging, asynchrony of chromosome disjunction, and tri-fission were found during the various developmental stages of PMC meiosis. All these abnormalities were significantly higher in sterile hybrids than in fertile hybrids, suggesting that pollen sterility gene interactions tend to increase the chromosomal abnormalities which cause the partial abortion of male gametes and leads to the decline in the seed set of the autotetraploid rice hybrids.