Decreasing the memory of the discontinuous Galerkin volume integral equation method for scattering from inhomogeneous dielectric objects.

A memory-efficient implementation scheme for the discontinuous Galerkin volume integral equation method (DGVIE) using Schaubert-Wilton-Glisson (SWG) basis functions is proposed to analyze electromagnetic scattering from inhomogeneous dielectric objects. For this proposed scheme, almost no half-SWG basis functions are needed for the elements separating nonconformal meshes, while these half-SWG basis functions are indispensable for the conventional DGVIE-SWG method. This is realized by applying the divergence-free condition of the electric displacement vector explicitly for nonconformal meshes separating neighboring subdomains of an inhomogeneous dielectric body. Therefore, the number of unknowns of the conventional DGVIE method can be further reduced. As a result, the memory of the proposed DGVIE method is only about half of the conventional one for inhomogeneous dielectric problems. Meanwhile, the total solution time has been reduced by the use of the proposed scheme. Particularly, the proposed DGVIE-SWG method is efficient in memory usage not only for inhomogeneous dielectric cases with high contrast ratio but also for cases with relatively low contrast ratio.

High-yield production of acidic pectin lyase PNLZJ5B for juice processing.

A pectin lyase gene pnlzj5b from Aspergillus niger ZJ5 was identified and overexpressed successfully in Pichia pastoris. Recombinant PNLZJ5B exhibited high activity towards citrus pectin (150 U ml-1 ). Through further codon optimization, the expression efficiency of PNLZJ5B in P. pastoris increased to 3·5-fold (532/150 U ml-1 ). PNLZJ5B was purified by ultrafiltration, anion exchange and gel chromatography. It showed optimal activity and good stability at 58°C and pH 4·5. PNLZJ5B activity improved with increasing degrees of methyl esterification of pectin. The Km and Vmax values were 0·81 mg ml-1 and 372·8 µmol min-1 mg-1 , respectively. In addition, PNLZJ5B effectively decreased the viscosity of apple juice. Compared with commercial pectin lyase, PNLZJ5B obtained a higher juice volume. These favourable enzymatic properties of PNLZJ5B show potential utility in juice-processing applications and other food-related fields.

[Analysis on characteristics and influencing factors of COVID-19 confirmed cases with viral nucleic acid re-positive after discharge in Guangdong Province].

Objective: To analyze the epidemiological characteristics and influencing factors of COVID-19 confirmed cases with viral nucleic acid re-positive in anal and/or throat swabs after discharge during the domestic imported epidemic stage in Guangdong Province in early 2020. Methods: The COVID-19 confirmed cases with the onset time before March 1, 2020 in Guangdong Province were collected to analyze the demographic data, epidemiological characteristics, and specimen collection and testing data after discharge. Logistic regression model was used for influencing factors analysis of re-positive cases. Results: A total of 1 286 COVID-19 confirmed cases were included, the M(Q1,Q3) of age was 44(32,58)years, 617 cases were male, 224 cases were re-positive in anal and/or throat swabs with the re-positive rate 17.42%. The M(Q1,Q3) of age of re-positive cases was 35(23, 50) years, which was younger than that of re-negative cases age was those 46(33, 59) years (P<0.001). With the increase of age, re-positive rate decreased (χ2trend=52.73, P<0.001). 85.27% (191/224) of re-positive cases were found in 14 d after discharge, the duration time of re-positive status was 13(7, 24) d, and 81.69% (183/224) of re-positive cases were re-tested negative in 28 d after re-positive date. No fever and other symptoms had been observed among re-positive cases during the whole follow-up. No secondary infectious cases had been found among close contacts after 14 d of centralized isolation and sampling screening. Univariate logistic regression model analysis revealed that the influencing factors of the re-positive cases included age, occupation, clusters, clinical types, and admission time. Multivariate logistic regression model analysis revealed that age was an independent risk factor. Conclusions: SARS-CoV-2 viral nucleic acid re-positive is found in COVID-19 confirmed cases after discharge in Guangdong Province. Most re-positive cases are confirmed among 14 d after discharge and re-test to negative among 28 d after re-positive date. Age is an risk factor for re-positive cases after discharge.

[Course of disease and related epidemiological parameters of COVID-19: a prospective study based on contact tracing cohort].

Objective: To analyze the course of disease and epidemiological parameters of COVID-19 and provide evidence for making prevention and control strategies. Methods: To display the distribution of course of disease of the infectors who had close contacts with COVID-19 cases from January 1 to March 15, 2020 in Guangdong Provincial, the models of Lognormal, Weibull and gamma distribution were applied. A descriptive analysis was conducted on the basic characteristics and epidemiological parameters of course of disease. Results: In total, 515 of 11 580 close contacts were infected, with an attack rate about 4.4%, including 449 confirmed cases and 66 asymptomatic cases. Lognormal distribution was fitting best for latent period, incubation period, pre-symptomatic infection period of confirmed cases and infection period of asymptomatic cases; Gamma distribution was fitting best for infectious period and clinical symptom period of confirmed cases; Weibull distribution was fitting best for latent period of asymptomatic cases. The latent period, incubation period, pre-symptomatic infection period, infectious period and clinical symptoms period of confirmed cases were 4.50 (95%CI:3.86-5.13) days, 5.12 (95%CI:4.63-5.62) days, 0.87 (95%CI:0.67-1.07) days, 11.89 (95%CI:9.81-13.98) days and 22.00 (95%CI:21.24-22.77) days, respectively. The latent period and infectious period of asymptomatic cases were 8.88 (95%CI:6.89-10.86) days and 6.18 (95%CI:1.89-10.47) days, respectively. Conclusion: The estimated course of COVID-19 and related epidemiological parameters are similar to the existing data.

Direct solution of the volume integral equation for electromagnetic scattering from dielectric objects with negative permittivity.

In this paper, electromagnetic scattering from dielectric objects with negative permittivity is solved by the volume integral equation (VIE)-hierarchical matrix (H-matrix)-based fast direct solver. To improve solution efficiency, a coarsening algorithm for the H-matrix is used, and the key parameter for the admissible condition is optimized through numerical experiments. Finally, the discontinuous Galerkin (DG) VIE (DGVIE) method is developed for the fast direct solver. It is shown that scattering from inhomogeneous dielectric objects with negative permittivity and with multiscale structure can be analyzed efficiently by the DGVIE-H-matrix-based fast direct solver.

Single Shot Characterization of High Transformer Ratio Wakefields in Nonlinear Plasma Acceleration.

Plasma wakefields can enable very high accelerating gradients for frontier high energy particle accelerators, in excess of 10 GeV/m. To overcome limits on single stage acceleration, specially shaped drive beams can be used in both linear and nonlinear plasma wakefield accelerators (PWFA), to increase the transformer ratio, implying that the drive beam deceleration is minimized relative to acceleration obtained in the wake. In this Letter, we report the results of a nonlinear PWFA, high transformer ratio experiment using high-charge, longitudinally asymmetric drive beams in a plasma cell. An emittance exchange process is used to generate variable drive current profiles, in conjunction with a long (multiple plasma wavelength) witness beam. The witness beam is energy modulated by the wakefield, yielding a response that contains detailed spectral information in a single-shot measurement. Using these methods, we generate a variety of beam profiles and characterize the wakefields, directly observing transformer ratios up to R=7.8. Furthermore, a spectrally based reconstruction technique, validated by 3D particle-in-cell simulations, is introduced to obtain the drive beam current profile from the decelerating wake data.

[Analysis on the cluster epidemic of coronavirus disease 2019 in Guangdong Province].

Objective: Analysis of clustering characteristics of coronavirus disease 2019 (COVID-19) in Guangdong Province. Methods: The COVID-19 cases in Guangdong Province onset from January 1 to February 29, 2020 were collected from Chinese information system for disease control and prevention and Emergency Public Reporting System. Obtain the epidemiological survey data of the cluster epidemic situation, and clarify the scale of cluster epidemic situation, the characteristics of the index cases, family and non-family subsequent cases. Calculate serial interval according to the onset time of the index cases and subsequent cases, secondary attack rate based on the close contacts tracking results, the characteristics of different cases in the clustered epidemic were compared. Results: A total of 283 cluster were collected, including 633 index cases, 239 subsequent cases. Families are mainly clustered, the total number involved in each cluster is in the range of 2-27, M (P25, P75) are 2.0 (2.0, 4.0). During January 15 to February 29, the secondary attack rate is 2.86% (239/8 363) in Guangdong Province, the family secondary attack rate was 4.84% (276/3 697), and the non-family secondary attack rate was 1.32% (61/4 632). According to the reporting trend of the number of cases in Guangdong Province, it can be divided into four stages, the rising stage, the high platform stage, the descending stage and the low level fluctuation period. The secondary attack rate of the four stages were 3.5% (140/3 987), 2.3% (55/2 399), 2.6% (37/1 435), 1.3% (7/542), respectively. The difference was statistically significant (P=0.003). Conclusion: COVID-19 cluster mainly occurs in families in Guangdong Province. The scale of the clustered epidemic was small; the serial interval was short; and the overall secondary attack rate was low.

MiR-1178-3p promotes the proliferation, migration and invasion of nasopharyngeal carcinoma Sune-1 cells by targeting STK4.

Nasopharyngeal carcinoma (NPC) is a malignant tumor with high invasive and metastatic properties. Dysregulation of miRNAs may contribute to disease progression by targeting disease-related genes. In this study we aimed to elucidate the role and function of aberrantly expressed miRNA in NPC tumorigenesis. We found that miR-1178-3p was highly expressed in NPC tissues. Overexpression of miR-1178-3p promoted the proliferation, migration and invasion of NPC cells in vitro. In contrast, knocking down endogenous miR-1178-3p by miRNA-specific inhibitor significantly suppressed the above phenotypes. Moreover, miR- 1178-3p was shown to negatively regulate serine/threonine-protein kinase 4 (STK4), an NPC-related tumor suppressor gene, in the post-transcriptional level. Furthermore, STK4 overexpression abolished miR-1178- 3p-induced cell proliferation, migration and invasion through STK4-mediated dephosphorylation of AKT. Our results indicate that miR-1178-3p acts as an oncomiRNA in NPC by suppressing STK4 expression, and inhibition of miR-1178-3p may become a therapeutic potential for NPC.

Fish consumption is associated with a decreased risk of death among adults with diabetes: 18-year follow-up of a national cohort.

BACKGROUND: There is a paucity of studies examining the beneficial effects of fish consumption on cardiovascular diseases (CVDs) among adults with diabetes, who experience a substantially high risk of CVDs. METHODS AND RESULTS: We analyzed the data of 1136 adults with diabetes mellitus aged 18 years and older who participated in the National Health and Nutrition Examination Survey, 1988-1994, and were followed up through December 31, 2010. We used Cox regression to estimate the adjusted hazard ratios (HRs) for the relative risk across the levels of fish consumption. A total of 698 deaths were recorded at the end of 11,465 person-years follow-up with a mortality rate of 60.88 per 1000 person-years. CVDs were listed as a contributing cause for 326 deaths, thus accounting for 46.4% of total deaths. Stroke-specific mortality rate among patients who ate fish less than once a week was more than twice as high as that among patients who ate fish more than twice a week, 6.23 vs. 2.36 per 1000 person-years, respectively. The corresponding CVD-specific rate was 34.38 vs. 22.99 per 1000 person-years, respectively. The adjusted HRs of death due to stroke were 1.00 (reference), 0.55 (95% confidence interval = 0.28-1.07), and 0.30 (0.11-0.80) among patients who ate fish <1, 1-2, and 2 + times a week, and the corresponding HRs of death due to CVDs were 1.00 (reference), 0.78 (0.60-1.02), and 0.69 (0.50-0.96), respectively. CONCLUSIONS: A high consumption of fish was associated with a low risk of death due to CVDs, especially stroke, among adults with diabetes.

[Impact of extended-spectrum ß-lactamase on clinical outcome and medical cost in patients with bloodstream infection due to Klebsiella pneumoniae].

OBJECTIVE: To evaluate the impact of extended-spectrum ß-lactamase (ESBL) on clinical outcome and medical cost in patients with bloodstream infection (BSI) due to Klebsiella pneumoniae. METHODS: A retrospective study was conducted in patients admitted into Changhai Hospital between January 2013 and December 2014, who suffered from BSI due to Klebsiella pneumoniae during hospitalization. Patients were divided into two groups according to whether Klebsiella pneumoniae produced ESBL (ESBL positive group and ESBL negative group). They were matched with propensity score matching method in a 1∶1 ratio and then multiple regression model was used to analyze the impact of ESBL on clinical outcome and medical cost. Clinical outcome was evaluated by 30-day mortality post BSI; medical cost was evaluated by total length of stay (LOS), post-BSI LOS, total hospital cost and antimicrobial cost. RESULTS: Before matching, the two groups were significantly different in age, nosocomial infection rate, LOS before BSI and surgical rate during hospitalization (all P<0.05). The ESBL-positive group had higher 30-day mortality post BSI (21.3% vs 8.7%, P=0.054), and higher total LOS [25.0(12.0, 33.0) vs 16.0(10.0, 23.0) d, P=0.015], post-BSI LOS [16.0(9.0, 26.0) vs 10.0(5.0, 16.0) d, P=0.006], total hospital cost [69 409(40 605, 198 021) vs 45 683(28 448, 67 000) ï¿¥, P<0.001] and antimicrobial cost [10 279(4 815, 25 500) vs 3 783(1 596, 11 879) ï¿¥, P<0.001]. After matching, the two groups had no significant differences in clinical characteristics such as sex, age, nosocomial infection rate, LOS before BSI, APACHEⅡ score, Charlson Comorbidity Index, underlying diseases and surgical rate during hospitalization (all P>0.05). Multiple regression analysis indicated that ESBL could significantly increase the total LOS, post-BSI LOS, total hospital cost and antimicrobial cost (all P<0.001), but did not increase the 30-day mortality post BSI (P=0.910). CONCLUSIONS: ESBL can significantly increase the medical cost in patients with BSI due to Klebsiella pneumoniae but does not increase the 30-day mortality post BSI.

[Empirical therapy of bloodstream infections caused by extended-spectrum ß-lactamase-producing Enterobacteriaceae].

OBJECTIVE: To compare the clinical outcomes and costs associated with carbapenems and ß-lactam/ß-lactamase inhibitor combinations (BLBLIs) for the empirical treatment of patients with extended-spectrum ß-lactamase (ESBL)-positive Enterobacteriaceae bloodstream infections (BSIs). METHODS: The medical records of individuals diagnosed with ESBL-producing Escherichia coli and Klebsiella pneumoniae BSIs between January 2014 and June 2015 at Changhai Hospital were reviewed. Patients were divided into two groups based on the empirical therapy (carbapenems group and BLBLIs group). Propensity score matching in a 1∶1 ratio was used to match the patients from two groups. Clinical outcomes and costs were compared before and after matching. RESULTS: One hundred and fifty-eight patients were analyzed, 93 in the carbapenems group and 65 in the BLBLIs group. Before matching, the two groups were significantly different in department distribution, tumor rate, deep vein catheter rate, urinary catheter rate, nasogastric tube rate, and mechanical ventilation rate (all P<0.05), and the carbapenems group had longer total length of stay (LOS) and post-BSI LOS (26.0 vs 18.0 d, P=0.029 and 12.0 vs 10.0 d, P=0.044) , higher hospital cost and daily hospital cost (84 120 vs 39 000 ï¿¥, P<0.001 and 3 451 vs 2 574 ï¿¥, P=0.002). After matching, the two groups had no significant differences in covariates such as sex, age, department distribution, pathogens, comorbidities, invasive interventions, LOS before BSI, multiple admissions, surgical rate during hospitalization and delayed antimicrobial therapy (all P>0.05). Finally, there were no differences between two groups in mortality, post-BSI LOS, total LOS, hospital cost and antimicrobial cost (all P>0.05). CONCLUSION: BLBLIs may provide a reasonable carbapenem-sparing option for the empirical treatment of ESBL producers.

Molecular events are associated with resistance to vinblastine in bladder cancer.

Bladder cancer occurs in the majority of cases in males, which represents the fourth highest incident cancer in men and tenth in women. It is associated with a high rate of recurrence, and prognosis is poor once the cancer metastasizes to distant sites. Transitional cell cancer (TCC) is the most predominant histological type. Bladder cancer is highly chemosensitive. However, the presence of acquired drug resistance is one of the primary impediments to the success of chemotherapy. To differentiate and delineate the molecular events, we developed drug resistant human transitional bladder cancer T24 cells (DRC) by treating cells with the increasing concentration of vinblastine. We found that DRC was resistant to vinblastine in comparison to parental T24 cells. We analyzed the contributory factors that may be involved in the development of resistance. As expected, expression of permeability glycoprotein (P—gp) was up—regulated in DRC. In addition, levels of Caveolin—1 (Cav—1), Fatty acid synthase (FASN) and Cytochrome P450 (CYP450) were elevated in DRC. Downregulation of these proteins by respective specific pharmacological inhibitors and/or by siRNAs resensitized cells to vinblastine. These results suggested that differential levels of P—gp, Cav—1 and FASN except CYP450 play a major role in acquired resistant phenotype in bladder cancer.

A 39-gene signature is associated with early occurrence of distant metastasis in primary lymph-node negative breast cancers.

Risk factors of the development of distant metastasis in primary node-negative breast cancer patients are heterogeneous. Identification of patients at high risk of early distant metastasis is of important clinical significance. In the current study, using the already published datasets, we develop a gene signature that can robustly predict early distant metastasis for patients with primary node-negative breast cancer. We identified a 39-gene signature, which were associated with distant metastasis and shorter distant metastasis free survival (DMFS) in node-negative breast cancers. Using the survival prediction analysis method in BRB-Array tools, this signature can stratify patients into early- and late- distant metastasis subgroups with different DMFS in VDX training dataset (AUC=0.734, P < 0.01). And we further validated the reliability of the prognostic value of this 39-gene signature in another two independent breast cancer cohorts (NKI dataset, AUC=0.642, P<0.0167; TRANSBIG dataset, AUC=0.711, P<0.0167). Furthermore, the early distant metastasis subgroups defined by the 39-gene signature exhibited a significant association with ER negative status and more aggressive molecular subtypes in all three datasets, and with poor differentiation status in two datasets. In summary, we developed a novel distant metastasis-related gene signature for predicting early occurrence of distant metastasis in node-negative breast cancers, what might be useful in making treatment decisions for these early metastasis patients.

COUP-TFII regulates metastasis of colorectal adenocarcinoma cells by modulating Snail1.

BACKGROUND: Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII, also known as NR2F2) promotes metastasis by functioning in the tumour microenvironment; however, the role of COUP-TFII in colorectal cancer remains unknown. METHODS: Human colon adenocarcinoma tissues were collected to test COUP-TFII expression. Wound-healing and cell invasion assay were used to evaluate migration and invasion of cells. Chicken ovalbumin upstream promoter-transcription factor II and related protein expression was assessed by immunostaining, immunoblotting and real-time PCR assay. Tamoxifen-inducible COUP-TFII knockout mice were employed to test COUP-TFII functions on colon cancer metastasis in vivo. RESULTS: Elevated expression of COUP-TFII in colorectal adenocarcinoma tissue correlated with overexpression of the Snail1 transcription factor. High COUP-TFII expression correlated with metastasis and shorter patient survival. Chicken ovalbumin upstream promoter-transcription factor II regulated the migration and invasion of cancer cells. With Snail1, COUP-TFII inhibited expression of adherence molecules such as ZO-1, E-cadherin and ß-catenin in colorectal cancer cells. Overexpression of COUP-TFII was required for cancer cells to metastasise in vivo. Chicken ovalbumin upstream promoter-transcription factor II regulated the transcription and expression of Snail1 by directly targeting the Snail1 promoter and regulated associated genes. CONCLUSIONS: Chicken ovalbumin upstream promoter-transcription factor II was crucial for colorectal cancer metastasis and regulated cell migration and metastasis in conjunction with Snail1. Chicken ovalbumin upstream promoter-transcription factor II was found to be a biomarker associated with patient survival and colorectal cancer metastasis.

Research on "The Belt and Road Initiative" report of think tank based on theme evolution and identification--Taking 2013-2020 as an example.

China's "the Belt and Road Initiative" (BRI) is a top-level cooperation initiative among countries proposed by China, which has promoted China's cooperation with relevant countries in various aspects and fields. Research reports from think tanks and experts on the evaluation, analysis, and research conclusions of the BRI can reflect the stance, opinions, and demands of various countries abroad regarding the initiative. This paper takes the BRI reports of important think tanks in the " Global Go To Think Tank Index Report 2020" as the subject of its research, and analyzes the key points and development trends of foreign think tank research on the BRI by using text mining, topic evolution, and social network analysis. It provides reasonable suggestions and ideas for promoting the construction of the BRI and deepening related cooperation in China. Research shows that the thematic distribution of research reports on the BRI by think tanks is mainly focused on the fields of politics, economy, and military. The research areas are relatively stable, and there is not a strong trend of thematic evolution. The evolution paths are also mainly distributed in the fields of politics, economy, and military. There are not many expansions in the thematic evolution directions over the years, and there is a strong inheritance of themes. The connection between research themes and the main purpose of the BRI is somewhat inadequate, indicating a certain limitation in the understanding of the BRI.

miR-499A>G rs3746444 and miR-146aG>C expression and hepatocellular carcinoma risk in the Chinese population.

We conducted a case-control study of a possible association of miR-499A>G rs3746444 and miR-146aG>C rs2910164 with risk of hepatocellular carcinoma. Samples from 172 hepatocellular carcinoma patients and 185 cancer-free controls were collected from October 2008 to December 2011. PCR-RFLP analysis was performed to determine the polymorphisms in each individual. The MAFs of miR-146aG>C and miR-499A>G in controls were similar to that known from the SNP database, and frequencies of genotypes in controls were in line with Hardy-Weinberg equilibrium. We found that miR-499 AG was significantly associated with decreased risk for hepatocellular carcinoma when compared with miR-499 AA genotype (adjusted odds ration = 0.74, 95% confidence interval = 0.24-0.96). However, subjects carrying miR-146a GG had a non-significant 0.62-fold decreased risk of hepatocellular carcinoma. We did not find a significant association of miR-146aG>C rs2910164 and miR-499A>G rs3746444 polymorphisms with hepatocellular carcinoma risk in the Chinese population. Further investigations are warranted to clarify the relationship between miRNA polymorphisms and susceptibility to hepatocellular carcinoma risk in various ethnic populations.

[Epidemiologic characteristics and influencing factors of influenza outbreaks in Guangdong Province, 2015-2022].

Objective: To grasp the epidemiological characteristics of influenza outbreaks in Guangdong Province by analyzing the outbreaks of influenza-like cases reported in Guangdong Province from January 2015 to the end of August 2022. Methods: In response to the outbreak of epidemics in Guangdong Province from 2015 to 2022, information on on-site epidemic control was collected, and epidemiological analysis was conducted to describe the characteristics of the epidemics. The factors that influence the intensity and duration of the outbreak were determined through a logistic regression model. Results: A total of 1 901 influenza outbreaks were reported in Guangdong Province, with an overall incidence of 2.05%. Most outbreak reports occurred from November to January of the following year (50.24%, 955/1 901) and from April to June (29.88%, 568/1 901). A total of 59.23% (1 126/1 901) of the outbreaks were reported in the Pearl River Delta region, and primary and secondary schools were the main places where outbreaks occurred (88.01%, 1 673/1 901). Outbreaks with 10-29 cases were the most common (66.18%, 1 258/1 901), and most outbreaks lasted less than seven days (50.93%,906/1 779). The size of the outbreak was related to the nursery school (aOR=0.38, 95%CI:0.15-0.93), the Pearl River Delta region (aOR=0.60, 95%CI:0.44-0.83), the time interval between the onset of the first case and the time of report (>7 days compared with ≤3 days: aOR=3.01, 95%CI:1.84-4.90), the influenza A(H1N1) (aOR=2.02, 95%CI:1.15-3.55) and the influenza B (Yamagata) (aOR=2.94, 95%CI: 1.50-5.76). The duration of outbreaks was related to school closures (aOR=0.65, 95%CI: 0.47-0.89), the Pearl River Delta region (aOR=0.65, 95%CI: 0.50-0.83) and the time interval between the onset of the first case and the time of report (>7 days compared with ≤3 days: aOR=13.33, 95%CI: 8.80-20.19; 4-7 days compared with ≤3 days: aOR=2.56, 95%CI: 1.81-3.61). Conclusions: An influenza outbreak in Guangdong Province exhibits two peaks, one in the winter and spring seasons and the other in the summer. Primary and secondary schools are high-risk areas, and early reporting of outbreaks is critical for controlling influenza outbreaks in schools. Furthermore, comprehensive measures should be taken to prevent the spread of the epidemic.

[Analysis of the impact of health management measures for entry personnel on imported Dengue fever in Guangdong Province, 2020-2022].

Objective: To explore the impact of health management measures for entry personnel (entry management measures) against COVID-19 on the epidemiological characteristics of imported Dengue fever in Guangdong Province from 2020 to 2022. Methods: Data of imported Dengue fever from January 1, 2016 to August 31, 2022, mosquito density surveillance from 2016 to 2021, and international airline passengers and Dengue fever annual reported cases from 2011 to 2021 in Guangdong were collected. Comparative analysis was conducted to explore changes in the epidemic characteristics of imported Dengue fever before the implementation of entry management measures (from January 1, 2016 to March 20, 2020) and after the implementation (from March 21, 2020 to August 31, 2022). Results: From March 21, 2020, to August 31, 2022, a total of 52 cases of imported Dengue fever cases were reported, with an imported risk intensity of 0.12, which were lower than those before implementation of entry management measures (1 828, 5.29). No significant differences were found in the characteristics of imported cases before and after implementation of entry management measures, including seasonality, sex, age, career, and imported countries (all P>0.05). 59.62% (31/52) of cases were found at the centralized isolation sites and 38.46% (20/52) at the entry ports. However, before implementation of entry management measures, 95.08% (1 738/1 828) of cases were found in hospitals. Among 51 cases who had provided entry dates, 82.35% (42/51) and 98.04% (50/51) of cases were found within seven days and fourteen days after entry, slightly higher than before implementation [(72.69%(362/498) and 97.59% (486/498)]. There was significant difference between the monthly mean values of Aedes mosquito larval density (Bretto index) from 2020 to 2021 and those from 2016 to 2019 (Z=2.83, P=0.005). There is a strong positive correlation between the annual international airline passengers volume in Guangdong from 2011 to 2021 and the annual imported Dengue fever cases (r=0.94, P<0.001), and a positive correlation also existed between the international passenger volume and the annual indigenous Dengue fever cases (r=0.72, P=0.013). Conclusions: In Guangdong, the entry management measures of centralized isolation for fourteen days after entry from abroad had been implemented, and most imported Dengue fever cases were found within fourteen days after entry. The risk of local transmission caused by imported cases has reduced significantly.

Expression of putative stem marker nestin and CD133 in advanced serous ovarian cancer.

It is hypothesized that "cancer stem cells" are responsible for the resistance to chemotherapy of cancer cells in ovarian cancers. The objective of the studies was to explore if the stem cell biomarkers could be used to predict the tumor chemotherapy-resistance in serous ovarian cancer patients. Expression of two putative stem cell markers CD133 and nestin, and vascular epithelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) were detected in 123 cases of advanced serous ovarian cancer specimens by immunohistochemistry. To estimate intra-tumoral microvessel density (MVD), CD34 immunostaining was also performed. CD133 and nestin were defined to be positive in 35.0% and 32.5% of the serous ovarian carcinoma tissues, respectively. It was observed that overexpression of nestin but not CD133 was associated with the cisplatin-based chemotherapy resistance and shorter overall survival of the patients, and nestin was found to be an independent prognostic factor. Moreover, positive nestin expression also correlated to increased expression of EGFR and VEGF, and elevated MVD in tumors. The results of this study suggest that serous ovarian cancers with high expression level of nestin represent an aggressive malignant phenotype associated with poor prognosis, and treatment targeted the nestin positive cancer cells might be a promising therapeutic strategy for this subgroups.

Effect of influenza on cardiorespiratory and all-cause mortality in Hong Kong, Singapore and Guangzhou.

1. Using a common modelling approach, mortality attributable to influenza was higher in the two subtropical cities Guangzhou and Hong Kong than in the tropical city Singapore. 2. The virus activity appeared more synchronised in subtropical cities, whereas seasonality of influenza tended to be less marked in the tropical city. 3. High temperature was associated with increased mortality after influenza infection in Hong Kong, whereas relative humidity was an effect modifier for influenza in Guangzhou. No effect modification was found for Singapore. 4. Seasonal and environmental factors probably play a more important role than socioeconomic factors in regulating seasonality and disease burden of influenza. Further studies are needed in identifying the mechanism behind the regulatory role of environmental factors.