[Based on CT radiomics model for predicting the response to first-line chemotherapy of diffuse large B-cell lymphoma]

Objective: To investigate the potential value of CT Radiomics model in predicting the response to first-line chemotherapy in diffuse large B-cell lymphoma (DLBCL). Methods: Pre-treatment CT images and clinical data of DLBCL patients treated at Shanxi Cancer Hospital from January 2013 to May 2018 were retrospectively analyzed and divided into refractory patients (73 cases) and non-refractory patients (57 cases) according to the Lugano 2014 efficacy evaluation criteria. The least absolute shrinkage and selection operator (LASSO) regression algorithm, univariate and multivariate logistic regression analyses were used to screen out clinical factors and CT radiomics features associated with efficacy response, followed by radiomics model and nomogram model. Receiver operating characteristic (ROC) curve, calibration curve and clinical decision curve were used to evaluate the models in terms of the diagnostic efficacy, calibration and clinical value in predicting chemotherapy response. Results: Based on pre-chemotherapy CT images, 850 CT texture features were extracted from each patient, and 6 features highly correlated with the first-line chemotherapy effect of DLBCL were selected, including 1 first order feature, 1 gray level co-occurence matrix, 3 grey level dependence matrix, 1 neighboring grey tone difference matrix. Then, the corresponding radiomics model was established, whose ROC curves showed AUC values of 0.82 (95% CI: 0.76-0.89) and 0.73 (95% CI: 0.60-0.86) in the training and validation groups, respectively. The nomogram model, built by combining validated clinical factors (Ann Arbor stage, serum LDH level) and CT radiomics features, showed an AUC of 0.95 (95% CI: 0.90-0.99) and 0.91 (95% CI: 0.82-1.00) in the training group and the validation group, respectively, with significantly better diagnostic efficacy than that of the radiomics model. In addition, the calibration curve and clinical decision curve showed that the nomogram model had good consistency and high clinical value in the assessment of DLBCL efficacy. Conclusion: The nomogram model based on clinical factors and radiomics features shows potential clinical value in predicting the response to first-line chemotherapy of DLBCL patients.

[A cohort study of incidence of club drug abuse in men who have sex with men in Qingdao]

Objective: To understand and analyze the incidence of club drug abuse and influencing factors in men who have sex with men (MSM) in Qingdao, and provide reference for the AIDS prevention and intervention in this population. Methods: From March 2017 to July 31, 2022, MSM who did not abuse club drug were recruited by snowball sampling of MSM social organizations in Qingdao, a prospective cohort was established, and a follow-up survey was conducted every 6 months. The survey collected the information about the MSM's demographic characteristics, sexual characteristics, club drug abuse and others. The incidence of club drug abuse was the outcome dependent variable and the interval between the recruitment into the cohort and the incidence of club drug abuse was the time dependent variable. Cox regression analysis was conducted to identify the influencing factors for club drug abuse. Results: A total of 509 MSM were recruited at baseline survey, and 369 eligible MSM were enrolled in this cohort. A total of 62 MSM began to abuse club drug during the study period, and the cumulative follow-up time was 911.54 person-years, the incidence of club drug abuse was 6.80/100 person-years. All the club drug abusers shared drugs with others in the first club drug abuse, and 16.13% (10/62) had mix-use of club drugs. The multivariate Cox proportional risk regression analysis showed that being students (aHR=2.17, 95%CI: 1.15-4.10), receiving no HIV testing or receiving 1 HIV testing during past 6 months (aHR=4.57, 95%CI:1.80-11.60; aHR=5.15, 95%CI: 2.83-9.36), having sex only with regular sexual partners during past 6 months (aHR=4.75,95%CI:2.32-9.75), having more than 4 homosexual partners (aHR=1.70, 95%CI:1.01-2.87) and abuse of club drug of sexual partners during past 6 months (aHR=12.78, 95%CI:3.06-53.35) were significantly associated with club drug abuse in the MSM. Conclusions: The incidence of club drug abuse was at a high level in the MSM cohort in Qingdao, indicating a high risk for HIV infection. Being student, receiving less HIV testing, having sex only with regular sexual partners, having more homosexual partners and abuse of club drug of sexual partners during past 6 months were risk factors for the incidence of club drug abuse in the MSM. Targeted surveillance and intervention measures should be strengthened to reduce the risk of club drug abuse in MSM.

Single cell sequencing unveils endothelial alterations after cisplatin treatment

Introduction

Cisplatin, one of the most potent anti-cancer chemotherapy drugs, is still broadly used in first-line chemotherapy regimens, which are subscribed to about 10 to 20% of total cancer patients. Nephrotoxicity is a particularly limiting factor for cancer patients to remain in the effective treatment due to the acute kidney injury. It has been reported that as early as 24 hours post treatment, testicular cancer patients receiving cisplatin developed endothelial dysfunction and vascular injury. A cross-sectional follow-up study published in 2008 suggested that testicular cancer survivors continued to experience endothelial dysfunction and vascular injury. A recent 30-year follow-up study on testicular cancer survivors suggested that testicular cancer survivors experienced worse diastolic function.

Purpose

This study is focused on identifying the specific genes altered in cardiac endothelial cells after the cisplatin treatment to unveil the molecular mechanisms of injury for potential new therapeutic development.

Methods

Cisplatin induced AKI mouse model was generated by i.p. injecting 25 mg/kg cisplatin to C57BL/6 mice. Saline injection was served as control. To evaluate blood vessel damage induced by cisplatin, mice were sacrificed 48 hours post injection. Hearts were collected and single cell suspensions were produced by using Multi Tissue Dissociation Kit 2. Freshly prepared single cell suspensions were used to created libraries by using 10X genomics kits, before sequencing. The CellRanger (10X genomics) was used for processing Single cell RNASeq outputs, before secondary Seurat and DE pathway analysis.

Results

The GO enrichment analysis suggested that, in endothelial cells, cisplatin treatment significantly altered cellular anatomical entity, intracellular anatomical structure, apical part of the cell, cell junction, and anchoring junction. Consequently, increased vascular permeability, signaling regulating monocyte differentiation, macrophage cytokine production, and cardiac muscle cell apoptosis were observed. At molecular level, cisplatin treatment significantly upregulated DNA damage (Ddit4, Acer2), hypoxia (Phlda3, Mt1, Slc3a2, Ier3, Klf9, Adipor2, UCP2), inflammatory responses (Timp4, Tns1, Gdf15, Neat1), cellular senescence (Cdkn1a), Cell cycle arrest (Trp53inpl), intrinsic and extrinsic apoptosis (Fas, Bax, Ei24, Tgm2), blood vessel remodeling (Pim-3), and angiogenesis (Timp3, Flt1). These results indicated that cisplatin treatment likely not only result in acute endothelial dysfunction, injury, and death, but also accelerated aging, which could contribute the cardiovascular complications in the cancer survivors.

Conclusions

Protecting endothelial cells from oxidative stress and inflammation caused by cisplatin treatment might prevent their irreversible injury and entering into premature cellular senescence, consequently, mitigating anti-cancer treatment induced cardiovascular complications in cancer survivors.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): NIH

Fluoride enrichment mechanisms and related health risks of groundwater in the transition zone of geomorphic units, northern China

Although groundwater is the primary drinking water source in northern of China, little is known about generation mechanisms and related health risks of high fluoride groundwater at the geomorphic transition zones. Thus, 419 groundwater samples were collected from Zhangjiakou region, where is a typically geomorphic transition zone of the North China Plain and the Inner Mongolia Plateau, to conduct the hydrochemical analysis, geochemical modeling, multivariate statistical analysis, and health risks assessment. From the results, F^- concentration in groundwater had a range of 0.05-9.71 mg L^-1. About 37.1% and 26.2% of groundwater samples from Bashang region (BSR) and Baxia region (BXR), respectively, were over the 1.50 mg L^-1, which were mainly distributed in the groundwater flow retardation area and/or evaporation discharge area. Thermodynamic simulations demonstrated that F-bearing minerals dissolution and Ca²⁺/Mg²⁺ removal via calcite/dolomite precipitation primarily governed high-F^- groundwater formation in the whole study area. Competitive adsorption, evaporation, evaporites dissolution and salt-effect also affected F^- enrichment in BSR. Desorption in alkaline environment, ion exchange and human activities played a vital role in F^- enrichment at BXR. The multivariate statistical analysis revealed that the origin of F^- contamination was geogenic in BSR; whereas, it was geogenic and anthropogenic in BXR. Besides, more than 71.8%, 51.0%, 36.1% and 25.5% of the study area exceeded the acceptable level (health index>1) for infants, children, adult males, and females, respectively. The health risks for different groups of people varied significantly and ranked: infants > children > males > females, suggesting that younger people were more susceptible to fluoride contamination. Meanwhile, females were more resistant to fluoride contamination than males. These findings are vital to providing insights on high-F^- groundwater formation, investigate the situation of health risks, and conduct the integrated management for high fluoride groundwater in geomorphic transition zones at northern China.

[Centromere protein U is highly expressed in colorectal cancer and associated with a poor long-term prognosis]

OBJECTIVE

To analyze the expression of centromere protein U (CENPU) in colorectal cancer and its predictive value for long-term prognosis of the patients.

METHODS

We retrospectively analyzed the data of 102 patients with colorectal cancer undergoing radical resection in our hospital between January, 2005 and December, 2011. The expression level of CENPU in colorectal cancer tissue was detected immunohistochemically, and its association with clinicopathological characteristics of the patients were analyzed. The patients were divided into low expression group (n=51) and high expression group (n=51) based on the median CENPU expression level for analysis the value of CENPU for predicting long-term prognosis of the patients after radical resection of the tumors. In the in vitro study, we constructed colorectal cancer cell lines with CENPU interference and CENPU overexpression by lentiviral transfection and assessed the changes in the proliferation, migration and invasion of the cells using CCK-8 assay and Transwell assay.

RESULTS

The protein expression level of CENPU was significantly higher in colorectal cancer tissues than in the adjacent tissues (P < 0.05) and was positively correlated with the expressions levels of Ki67 (r=0.569, P < 0.05) and VEGF-C (r=0.629, P < 0.05). CENPU expression level in colorectal cancer tissue was closely related with tumor progression and clinicopathological stage of the tumor (P < 0.05). Kaplan-Meier survival analysis showed that the patients with high CENPU expression had significantly decreased postoperative overall survival (χ²=11.155, P < 0.05); Cox multivariate regression analysis suggested that CENPU expression level was an independent risk factor affecting the overall survival of the patients after radical resection (HR=1.848, P < 0.05). The results of cell experiments demonstrated that high CENPU expression significantly promoted the proliferation, migration and invasion of the tumor cells.

CONCLUSION

CENPU is highly expressed in colorectal cancer tissues in closely correlation with tumor progression and may serve as a potential biomarker for evaluating the long-term prognosis of colorectal cancer patients.

[Construction of an adenovirus vector expressing engineered splicing factor for regulating alternative splicing of YAP1 in neonatal rat cardiomyocytes]

OBJECTIVE

To construct an adenovirus vector expressing artificial splicing factor capable of regulating alternative splicing of Yap1 in cardiomyocytes.

METHODS

The splicing factors with different sequences were constructed against Exon6 of YAP1 based on the sequence specificity of Pumilio1. The PCR fragment of the artificially synthesized PUF-SR or wild-type PUFSR was cloned into pAd-Track plasmid, and the recombinant plasmids were transformed into E. coli DH5α for plasmid amplification. The amplified plasmids were digested with Pac I and transfected into 293A cells for packaging to obtain the adenovirus vectors. Cultured neonatal rat cardiomyocytes were transfected with the adenoviral vectors, and alternative splicing of YAP1 was detected using quantitative and semi-quantitative PCR; Western blotting was performed to detect the signal of the fusion protein Flag.

RESULTS

The transfection efficiency of the adenovirus vectors was close to 100% in rat cardiomyocytes, and no fluorescent protein was detected in the cells with plasmid transfection. The results of Western blotting showed that both the negative control and Flag-SR-NLS-PUF targeting the YAPExon6XULIE sequence were capable of detecting the expression of the protein fused to Flag. The results of reverse transcription-PCR and PCR demonstrated that the artificial splicing factor constructed based on the 4th target sequence of YAP1 effectively regulated the splicing of YAP1 Exon6 in the cardiomyocytes (P < 0.05).

CONCLUSION

We successfully constructed adenovirus vectors capable of regulating YAP1 alternative splicing rat cardiomyocytes.

[Characteristics and changes of sensitization patterns of major allergens in children from 2010 to 2020 in a hospital of pediatric in Beijing]

Objective: To analyze the sensitization characteristics and change of major allergens in children from 2010 to 2020 in Beijing, so as to provide basis for diagnosis, treatment and prevention of allergic diseases in children. Methods: A retrospective study was conducted to analyze the children who were suspected of allergic diseases and tested for serum immunoglobulin E (total IgE and specific IgE) in the children's Hospital Affiliated to the Capital Institute of Pediatrics from January 2010 to December 2020. A total of 45 746 children aged 0-17 years in Beijing were enrolled with a median (interquartile range) of 3.8 (2.5, 5.3) years. There were 28 918 boys (63.2%) and 16 828 girls (36.8%) and 14 984 cases (32.8%) in the infant group (<3 years old), 22 049 cases (48.2%) in the preschool group (3-6 years old), and 8 713 cases (19.0%) in the school-age group (6 years old and above). Immunocap allergen detection system (fluorescence enzyme-linked immunosorbent assay) was used to detect and the characteristics and change trend of allergens during 11 years were statistically analyzed by Chi square test. Results: The top three positive rates of single food allergens sIgE were egg white 42.6% (2 788/6 577 tests), milk 38.4% (2 606/6 782 tests) and wheat 31.8% (1 417/4 449 tests), and the sequence of single inhaled allergens were Ragweed 42.6% (440/1 034 tests), Artemisia 38.4% (1 045/3 191 tests) and Alternaria alternata 31.3% (3 358/10 725 tests). The positive detection rates of egg white 47.0%(1 904/4 048 tests), milk 41.9%(1 769/4 226 tests) and wheat 33.9%(973/2 870 tests) in the infant group were the highest, and there have statistically significant(χ²=91.495, 73.907, 16.966, P<0.05). The positive rates of fx1 (22.5%, 121/537 tests), peanut (24.9%, 111/446 tests), soybean (20.0%, 74/370 tests) and shrimp (7.48%, 44/588 tests) were the highest in the school-age group(χ²=14.436, 10.751, 11.569, 13.703, P<0.05). The most common inhaled allergens were Alternaria alternata (14.8%, 422/2 859 tests) in the infant group, Ambrosia (34.5%, 143/415 tests) and Alternaria alternata (33.5%, 1 762/5 254 tests) in the preschool group, while in the school-age group were Ambrosia (56.4%, 282/500 tests) and Artemisia (48.2%, 573/1 189 tests). The positive rates of egg white, milk, wheat, sesame seed and peanut varied from 2010 to 2020, showing a trend of falling first and then rising(χ²=10.293,χ²=12.066,χ²=7.402,χ²=32.458,χ²=31.747,P<0.05).The positive detection rates of soybean showed a significant downward trend (21.4%, 173/809 tests in 2010, 15.4%, 70/455 tests in 2020, χ²=6.751,P=0.009), while that of shrimp and crab were at a stable low level(χ²=0.263, 1.346;P>0.05). From 2010 to 2020, mold (26.7%, 1 066/3 998 tests in 2010, 40.2% 1 705/4 243 tests in 2020), grass pollen (19.8%, 259/1 308 tests in 2010, 39.3%, 1 472/3 746 tests in 2020), tree pollen(17%, 180/1 058 tests in 2010, 29.8%, 916/3 075 tests in 2020) and animal dander (18.5%, 111/601 tests in 2010, 26.6%, 672/2 522 tests in 2020) were all showed significant upward trend (χ²=168.600, 163.601, 65.931 and 17.271 respectively, P<0.001) but dust mites (30.7%, 1 270/4 132 tests in 2010, 26.7%, 1 126/4 221 tests in 2020) showed a significant downward trend(χ²=16.822,P<0.001).In 2010, the most common inhaled allergen was dust mite 30.7% (1 270/4 132 tests), followed by mold 26.7% (1 066/3 998 tests), while they were mold 40.2% (1 705/1 243 tests), and grass pollen 39.3% (1 472/3 746 texts) respectively in 2020. Conclusion: In the past 11 years, the main food allergens in children were still egg white and milk, wheat, but the mold and pollen gradually replaced dust mite as the most common inhaled allergen.

[ALDH3B1 expression is correlated with histopathology and long-term prognosis of gastric cancer]

OBJECTIVE

To investigate the expression of aldehyde dehydrogenase 3B1 (ALDH3B1) in gastric cancer and explore its correlation with the pathological parameters and long-term prognosis of the patients.

METHODS

We analyzed the clinical data of 101 patients who underwent radical gastrectomy for gastric cancer in our hospital between January, 2013 and November, 2016, and examined the expression of ALDH3B1 in paraffin-embedded samples of gastric cancer tissues and adjacent tissues from these cases by immunohistochemical staining. We evaluated the correlation between ALDH3B1 expressions and histopathological parameters and assessed the predictive value of ALDH3B1 expression for long-term survival of the patients. We also examined the effect of lentivirus-mediated interference and overexpression of ALDH3B1 on the malignant behaviors of MGC-803 gastric cancer cells.

RESULTS

The expressions of ALDH3B1 and Ki67 were significantly higher in gastric cancer tissues than in adjacent tissues (P < 0.05). In gastric cancer patients, ALDH3B1 expression was positively correlated with peripheral blood CEA and CA19-9 levels (P < 0.01). The proportion of patients with CEA ≥5 μg/L, CA19-9 ≥37 kU/L, T stage of 3- 4, and N stage of 2-3 was significantly greater in high ALDH3B1 expression group than in low expression group. Kaplan-Meier survival analysis showed that the 5-year survival rate was significantly lower in gastric cancer patients with high ALDH3B1 expressions (P < 0.01). Univariate and Cox multiple regression analyses identified a high expression of ALDH3B1 (P < 0.05, HR= 0.231, 95% CI: 0.064-0.826), CEA≥5 μg/L (P < 0.01, HR=4.478, 95% CI: 1.530-13.110), CA19-9≥37 kU/L (P < 0.01, HR=3.877, 95% CI: 1.625-9.247), T stage of 3-4 (P < 0.01, HR=4.953, 95% CI: 1.768-13.880), and N stage of 2-3 (P < 0.05, HR=2.152, 95% CI: 1.152-4.022) as independent risk factors affecting 5-year survival after radical gastrectomy. The relative ALDH3B1 expression level, at the cut-off point of 4.66, showed a sensitivity of 76.47% and a specificity of 76% for predicting 5-year postoperative death (P < 0.01). In the cell experiment, overexpression of ALDH3B1 obviously promoted the proliferation, migration and invasion of MGC-803 cells.

CONCLUSION

As an independent risk factor affecting 5-year survival after radical gastrectomy, ALDH3B1 is highly expressed in gastric cancer and correlated with pathological parameters of the tumor, and a high ALDH3B1 expression may promote proliferation, invasion and metastasis of gastric cancer cells.

Targeting a gene regulatory element enhances rice grain yield by decoupling panicle number and size

Crop genetic improvement requires balancing complex tradeoffs caused by gene pleiotropy and linkage drags, as exemplified by IPA1 (Ideal Plant Architecture 1), a typical pleiotropic gene in rice that increases grains per panicle but reduces tillers. In this study, we identified a 54-base pair cis-regulatory region in IPA1 via a tiling-deletion-based CRISPR-Cas9 screen that, when deleted, resolves the tradeoff between grains per panicle and tiller number, leading to substantially enhanced grain yield per plant. Mechanistic studies revealed that the deleted fragment is a target site for the transcription factor An-1 to repress IPA1 expression in panicles and roots. Targeting gene regulatory regions should help dissect tradeoff effects and provide a rich source of targets for breeding complementary beneficial traits.

[Safety and efficacy of left atrial appendage closure combined with patent foramen ovale closure for atrial fibrillation patients with patent foramen ovale]

Objective: To analyze the safety and efficacy of combined left atrial appendage (LAA) and patent foramen ovale (PFO) closure in adult atrial fibrillation (AF) patients complicating with PFO. Methods: This study is a retrospective and cross-sectional study. Seven patients with AF complicated with PFO diagnosed by transesophageal echocardiography (TEE) in Zhoupu Hospital Affiliated to Shanghai University of Medicine & Health Sciences from June 2017 to October 2020 were selected. Basic data such as age, gender and medical history were collected. The atrial septal defect or PFO occluder and LAA occluder were selected according to the size of PFO, the ostia width and depth of LAA. Four patients underwent left atrial appendage closure(LAAC) and PFO closure at the same time. PFO closure was performed during a one-stop procedure of cryoablation combined with LAAC in 2 patients. One patient underwent PFO closure at 10 weeks after one-stop procedure because of recurrent transient ischemic attack (TIA). All patients continued to take oral anticoagulants. TEE was repeated 8-12 weeks after intervention. In case of device related thrombus(DRT), TEE shall be rechecked 6 months after adjusting anticoagulant and antiplatelet drug treatment. Patients were follow-up at 1, 3, 6, 12, 24 months by telephone call, and the occurrence of cardio-cerebrovascular events was recorded. Results: Among the 7 patients with AF, 2 were male, aged (68.0±9.4) years, and 3 had a history of recurrent cerebral infarction and TIA. Average PFO diameter was (3.5±0.8)mm. Three patients were implanted with Watchman LAA occluder (30, 30, 33 mm) and atrial septal defect occluder (8, 9, 16 mm). 2 patients were implanted with LAmbre LAA occluder (34/38, 18/32 mm) and PFO occluder (PF1825, PF2525). 2 patients were implanted with LACbes LAA occluder (24, 28 mm) and PFO occluder (PF2525, PF1825) respectively. The patients were followed up for 12 (11, 24) months after operation. TEE reexamination showed that the position of LAA occluder and atrial septal defect occluder or PFO occluder was normal in all patients. DRT was detected in 1 patient, and anticoagulant therapy was adjusted in this patient. 6 months later, TEE showed that DRT disappeared. No cardiovascular and cerebrovascular events occurred in all patients with AF during follow-up. Conclusions: In AF patients complicated with PFO, LAAC combined with PFO closure may have good safety and effectiveness.

Automatic assessment of dairy cows' rumen function over time and links to feed changes and milk production

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We monitored rumen function longitudinally in dairy cows using a 3-dimensional (3D) vision-based system.

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Rumen function was associated with feed changes and milk production.

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Early-spring grazing reduced rumen fill and milk fat content in cows.

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A cow with rumen dysfunction showed deviations in rumen motility in the 3D vision system.

A 3-dimensional (3D) vision-based system was previously designed to automatically estimate the rumen motility of individual cows. This longitudinal study aimed to explore the associations between 3D vision-based rumen function assessment and dairy cow feed changes and milk production on a commercial farm. The 3D vision system was attached to an automatic milking robot to estimate the ruminal contraction frequency and rumen fill in 42 lactating cows during each milking event for 66 d. Additionally, we collected data on milk production, milk composition, general health, and changes in feeding practices. The 3D vision system showed that half the cows displayed a drastic decrease in the estimated rumen fill when all cows began grazing. The grazing and decreased rumen fill were also associated with herd-level milk fat depression. Over the 66 d, one cow was detected with reduced milk production and suspected rumen dysfunction by the farmer. The 3D vision system, however, identified this cow as having sudden decreases in estimated ruminal contraction frequency and rumen fill 4 d before detection by the farmer. In this longitudinal study, the 3D vision-based rumen function assessment system showed potential as a useful management-supporting tool for dairy farmers. The system, however, requires further validation with more cows of various breeds and ages. We suggest validating the 3D vision system with rumen boluses, quantified adjustments in feeding practices, more cases with ruminal dysfunction, and systematic health assessments for future studies.

[Effects of unsafe sexual behavior and sexual orientation on previous HIV testing and HIV testing willingness among college students in Harbin]

Objective: To analyze the effects of unsafe sexual behavior and sexual orientation on previous HIV testing and HIV testing willingness among college students in Harbin, to provide a theoretical basis for promoting and promoting HIV testing among them. Methods: A cross-sectional survey design was used to place the automatic vending machine of HIV urine test kit in 9 universities in Harbin from December 2017 to January 2018. The questionnaire star was used to design and recruit college students to carry out an anonymous online survey. The estimated sample size was 6 659. A multivariate logistic regression model was used to analyze the effects of unsafe sexual behavior and sexual orientation on previous HIV testing and HIV testing willingness among college students. WPS 2016 was used to sort out the database, and SPSS 21.0 software was used for statistical analysis. Results: A total of 60 849 valid questionnaires were collected. 19.1% (11 189/58 605) of college students reported having sex. College students who used condoms correctly every time, occasionally or never during sex in the past six months 58.5% (6 206/10 603), 25.2%(2 669/10 603)and 16.3% (1 728/10 603), respectively. Heterosexuality, homosexuality and bisexuality accounted for 94.1% (54 393/57 823), 2.4% (1 369/57 823) and 3.5% (2 061/57 823), respectively. The HIV testing willingness of college students was 73.3% (44 572/60 849). The proportion of previous HIV testing was 10.3% (951/9 241). Results of the multivariate logistic analysis showed that compared with the college students who used condoms correctly whenever they had sex in the past six months, there was no significant difference in the proportion of previous HIV testing among college students who sometimes/occasionally used or never used condoms (OR=0.94,95%CI:0.69-1.29; OR=1.11,95%CI:0.73-1.67), but their willingness to HIV testing was lower (OR=0.79, 95%CI:0.71-0.89; OR=0.48, 95%CI:0.42-0.55); Compared with heterosexual college students, homosexual or bisexual college students have a higher proportion of previous HIV testing (OR=2.62, 95%CI:1.62-4.24; OR=2.04, 95%CI:1.25-3.32), but have lower HIV testing willingness (OR=0.76, 95%CI: 0.62-0.93; OR=0.64, 95%CI: 0.53-0.77). Conclusions: Unsafe sexual behavior existed among college students in Harbin, and college students with weak awareness of HIV prevention also have weak awareness of testing. Behavioral intervention should be strengthened and HIV testing promoted. Compared with heterosexuals, homosexual or bisexual college students had a higher proportion of previous HIV testing, but their willingness to test was lower. The HIV detection mode with better concealment, accuracy, and convenience should be promoted on the college's campus.

A high precision phase measurement system implemented in FPGA with phase interpolator

High precision timing distribution is crucial to many large scale cosmology and particle physics experiments. Besides the space and energy information, the accurate timing provides an extra dimension for physics event reconstruction. In the timing distribution system, accurate clock phase measurement is an indispensable tool to monitor the phase drift and to achieve accurate phase adjustment. This paper introduces a novel phase measurement method implemented in the Xilinx Field Programmable Gate Array (FPGA). It uses the dedicated phase interpolator in the multi-gigabit transceiver. A design based on this method is implemented within the Kintex Ultrascale series FPGA. The preliminary test result shows that a sub-picosecond level precision is achieved. With this system, the nonlinearity of the phase adjustment in the Xilinx transceiver is measured.