[Development and outlook on human challenge trial of vaccine]

Human challenge trial (HCT) is a test in which human volunteers are intentionally infected with pathogens in order to evaluate the efficacy of candidate preventive or therapeutic drugs. During the COVID-19 pandemic, the HCT of vaccines has aroused people's attention due to its significant advantages over clinical trial. This paper introduces the concept, development and application of HCT, the advantages and limitations of HCT for vaccine evaluation, and the consideration of future HCT of COVID-19 vaccine in China.

[A multicenter retrospective study on the etiology of necrotizing pneumonia in children]

Objective: To investigate the etiology of necrotizing pneumonia (NP) in children and the clinical characteristics of NP caused by different pathogens in China. Methods: A retrospective, case-control study was performed in children with NP who were admitted to 13 hospitals in China from January 2008 to December 2019. The demographic and clinical information, laboratory data, etiological and radiological findings were analyzed. The data were divided into three groups based on the following years: 2008-2011, 2012-2015 and 2016-2019, and the distribution characteristics of the pathogens in different period were compared. Meanwhile, the pathogens of pediatric NP in the southern and northern China were compared. And the clinical characteristics of the Mycoplasma pneumoniae (MP) NP and the bacterial NP were also compared. T-test or Mann-Whitney nonparametric test was used for comparison of numerical variables, and χ² test was used for categorical variables. Results: A total of 494 children with NP were enrolled, the median ages were 4.7 (0.1-15.3) years, including 272 boys and 222 girls. Among these patients, pathogens were identified in 347 cases and the pathogen was unclear in the remaining 147 cases. The main pathogens were MP (238 cases), Streptococcus pneumoniae (SP) (61 cases), Staphylococcus aureus (SA) (51 cases), Pseudomonas aeruginosa (13 cases), Haemophilus influenzae (10 cases), adenovirus (10 cases), and influenza virus A (7 cases), respectively. MP was the most common pathogen in all three periods and the proportion increased yearly. The proportion of MP in 2016-2019 was significantly higher than that in 2012-2015 (52.1% (197/378) vs. 36.8% (32/87), χ²=6.654, P=0.010), while there was no significant difference in the proportion of MP in 2012-2015 and that in 2008-2011 (36.8% (32/87) vs. 31.0% (9/29), χ²=0.314, P=0.575).Regarding the regional distribution, 342 cases were in the southern China and 152 in the northern China. Also, MP was the most common pathogen in both regions, but the proportion of MP was higher and the proportion of SP was lower in the north than those in the south (60.5% (92/152) vs. 42.7% (146/342), χ²=13.409, P<0.010; 7.9% (12/152) vs. 14.3% (49/342), χ²=4.023, P=0.045). Comparing the clinical characteristics of different pathogens, we found that fever and cough were the common symptoms in both single MP and single bacterial groups, but chest pain was more common (17.0% (34/200) vs. 6.1% (6/98), χ²=6.697, P=0.010) while shortness of breath and wheezing were less common in MP group (16.0% (32/200) vs. 60.2% (59/98), χ²=60.688, P<0.01; 4.5% (9/200) vs. 21.4% (21/98), χ²=20.819, P<0.01, respectively). The white blood cell count, C-reactive protein and procalcitonin in the bacterial group were significantly higher than those in the MP group (14.7 (1.0-67.1)×10⁹/L vs. 10.5 (2.5-32.2)×10⁹/L, 122.5 (0.5-277.3) mg/L vs. 51.4 (0.5-200.0) g/L, 2.13 (0.05-100.00) μg/L vs. 0.24 (0.01-18.85) μg/L, Z=-3.719, -5.901 and -7.765, all P<0.01). Conclusions: The prevalence of pediatric NP in China shows an increasing trend during the past years. MP, SP and SA are the main pathogens of NP, and the most common clinical symptoms are fever and cough. The WBC count, C-reactive protein and procalcitonin in bacterial NP are significantly higher than those caused by MP.

[Anatomical controversies involved in radical resection of rectal cancer]

The concept of total mesorectal resection provides a quality control standard that can be followed for radical resection of rectal cancer, but some anatomical problems are still controversial. Compared with traditional open surgery, laparoscopic radical rectal surgery has better surgical vision, better neurological protection, better operating space. However, if the surgeon has insufficient understanding of the anatomy, collateral damage may occur, such as uncontrollable bleeding during the operation, postoperative urination and defecation dysfunction and so on. Based on the interpretation of the researches at home and abroad, combined with the clinical experience, we elucidate some associated issues, including anatomic variation of inferior mesenteric vessels, the controversy of inferior mesenteric artery ligation plane, the controversy of lymph node dissection in No. 253, the anatomical variation of middle rectal artery, and the anatomical controversy of lateral lymph node dissection in rectal cancer, in order to provide better cognitive process for the clinical front-line surgeons.

[Association between polygenic risk score and age at onset of gastric cancer]

Objective: To explore the association between polygenic risk score (PRS) and age at onset and early-onset risk of gastric cancer (GC). Methods: Gastric cancer cases from existing genome-wide association study were included, and 112 single nucleotide polymorphisms associated with GC risk were used to derive individual PRS. Analysis of variance and Pearson correlation test was used to depict the relationship between PRS and GC onset age. Cases diagnosed before 50 years old were defined as early-onset gastric cancer. Cox proportional hazard model was used to test the association between PRS and early-onset GC risk with early-onset age as the timescale and low genetic risk (PRS ≤20%) as the reference group. Results: A total of 8 629 cases, including 6 284 males (72.82%) and 2 345 females (27.18%), were included, and the mean age was (60.61±10.80) years old. The PRS was negatively correlated with age of GC onset (r=-0.05, P<0.001). The mean age of gastric cancer cases with low, intermediate, and high genetic risk were (61.68±10.33), (60.53±10.79), (59.80±11.20), respectively. PRS was significantly associated with the risk of early-onset GC in a dose-response manner (intermediate genetic risk: HR=1.19, 95%CI: 1.03-1.39, P=0.022; high genetic risk: HR=1.44, 95%CI: 1.20-1.71, P<0.001). Conclusions: PRS may contribute to the risk of both GC and early-onset GC. PRS can be used as a measurable indicator for risk prediction for occurrence and early-onset of GC.

Impact of a novel Rickettsia symbiont on the life history and virus transmission capacity of its host whitefly (Bemisia tabaci)

Rickettsia consists of some of the most prevalent symbionts of insects and often plays a significant role in the biology of its hosts. Recently, a maternally inherited Torix group Rickettsia, provisionally named as RiTBt, was recorded in a species of notorious pest whitefly, tentatively named as Asia II 1, from the Bemisia tabaci complex. The role of this Rickettsia in the biology of its host is unknown. Here we investigated the impact of RiTBt on the performance and virus transmission capacity of Asia II 1. RiTBt did not significantly affect the life history parameters of the whitefly when the host insect was reared on tobacco, tomato, and cotton, three host plants with relatively low, medium and high suitability to the whitefly. Intriguingly, RiTBt slightly enhanced whitefly transmission of cotton leaf curl Multan virus (CLCuMuV), a virus that is transmitted by the whitefly in the field and has caused extensive damage to cotton production. Specifically, compared with whiteflies without RiTBt, following a 48 h virus acquisition whiteflies with RiTBt had higher titer of virus and showed higher efficiency of virus transmission. A rickettsial secretory protein BtR242 was identified as a putative virus-binding protein, and was observed to interact with the coat protein of CLCuMuV in vitro. Viral infection of the whitefly downregulated gene transcript levels of the BtR242 gene. These observations indicate that RiTBt has limited impact on the biology of the Asia II 1 whitefly, and whether this symbiont has functions in the biology of other host whiteflies warrants future investigation.

Functional Analysis of Alkaline Phosphatase in Whitefly Bemisia tabaci (Middle East Asia Minor 1 and Mediterranean) on Different Host Plants

Alkaline phosphatases (ALPs: EC 3.1.3.1) are ubiquitous enzymes and play crucial roles in the fundamental phosphate uptake and secretory processes. Although insects are regarded as the most diverse group of organisms, the current understanding of ALP roles in insects is limited. As one type of destructive agricultural pest, whitefly Bemisia tabaci, a phloem feeder and invasive species, can cause extensive crop damage through feeding and transmitting plant diseases. In this study, we retrieved five ALP genes in MEAM1 whitefly, nine ALP genes in MED whitefly via comparative genomics approaches. Compared with nine other insects, whiteflies' ALP gene family members did not undergo significant expansion during insect evolution, and whiteflies' ALP genes were dispersed. Moreover, whiteflies' ALP gene family was conserved among insects and emerged before speciation via phylogenetic analysis. Whiteflies' ALP gene expression profiles presented that most ALP genes have different expression patterns after feeding on cotton or tobacco plants. Female/male MED whiteflies possessed higher ALP activities on both cotton and tobacco plants irrespective of sex, relative to MEAM1 whiteflies. Meanwhile, adult MED whiteflies possessed higher ALP activity in both whole insect and salivary samples, relative to MEAM1 whiteflies. We also found that both MED and MEAM1 whiteflies could upregulate ALP activities after feeding on cotton compared with feeding on tobacco plants. These findings demonstrated the functions of whiteflies ALPs and will assist the further study of the genomic evolution of insect ALPs.

[Impact of systolic blood pressure on outcome of patients with nonvalvular atrial fibrillation]

Objective: To investigate the impact of different levels of systolic blood pressure on all-cause, cardiovascular and cerebrovascular mortality in patients with nonvalvular atrial fibrillation (AF). Methods: This is a prospective cohort study. Patients with AF or atrial flutter diagnosed by 12 lead electrocardiogram during physical examination of Kailuan Group employees from July 2006 to December 2017 or previously diagnosed with AF in an inpatient setting at a level 2A hospital or above were eligible for the study. Baseline clinical characteristics including age, gender, systolic blood pressure were collected. According to the level of systolic blood pressure, patients were divided into systolic blood pressure<120 mmHg (1 mmHg=0.133 kPa)group, 120 mmHg ≤ systolic blood pressure<140 mmHg group, and systolic blood pressure ≥140 mmHg group. The time of first diagnosis with AF was defined as the start of follow-up and the final follow-up ended at December 2018. Primary endpoint was all-cause death. Related information was obtained through the social security system or inpatient medical records. The cause of death was defined according to the International Classification of Diseases disease (ICD-10) codes by professional medical stuffs. Multifactorial Cox proportional risk model was used to analyze the relative risk ratios for the occurrence of death in different systolic blood pressure level groups. The relationship between systolic blood pressure levels and mortality in the patients with AF was analyzed by using natural spline function curves. Results: A total of 1 721 patients with AF were enrolled (average age=(67.0±9.0) years), patients were followed up for (6.3±3.8) years. 544 out of 1 721 patients with AF died during the follow-up period (31.61%). The cumulative incidence rate of all-cause mortality, cardiovascular and cerebrovascular death was 26.13%, 25.59%, 36.96% and 14.86%, 11.87%, 19.76% respectively in the systolic blood pressure<120 mmHg, 120 mmHg ≤ systolic blood pressure<140 mmHg and systolic blood pressure ≥140 mmHg groups. The cumulative incidence rate of all-cause, cardiovascular and cerebrovascular death was significantly higher in the group with systolic blood pressure ≥140 mmHg than in 120 mmHg ≤ systolic blood pressure<140 mmHg group (P<0.05). Compared with 120 mmHg ≤ systolic blood pressure<140 mmHg group, multivariable Cox proportional hazards regression models showed that the HRs (95%CI) for all-cause, cardiovascular and cerebrovascular death were 1.47 (1.20 to 1.79) and 1.69 (1.27 to 2.26) for the group with systolic blood pressure ≥ 140 mmHg (P<0.05). In contrast, the HRs (95%CI) for all-cause, cardiovascular and cerebrovascular death in the systolic blood pressure<120 mmHg group were 0.99 (0.73-1.35) and 1.24 (0.82-1.89), respectively, with no statistically significant differences between the two groups (P>0.05). The natural spline curve showed that there was a "U" relationship between systolic blood pressure levels and all cause death and cardiovascular and cerebrovascular death in this patient cohort. Systolic blood pressure greater than or less than 123 mmHg was associated with increased risk of death of AF patients in this cohort. Conclusion: Compared with systolic blood pressure<120 mmHg and systolic blood pressure≥140 mmHg group, the risk of all-cause and cardiovascular and cerebrovascular death is the lowest in AF patients with 120 mmHg ≤ systolic blood pressure<140 mmHg in this cohort.

[Formaldehyde and xylene levels and protective effects in the pathology department of a hospital]

Objective: To investigate the status of exposure to xylene and Formaldehyde of medical and technical personnel in Pathology Department of a hospital, and to provide references for prevention of occupational hazards. Methods: From July to October in 2019, 52 medical workers and working places in Pathology Department of a third-class hospital in Jiangxi Province were selected as survey objects, the distribution of occupational hazards, protective measures and personal protective equipment were investigated, and the control wind speed of Formaldehyde, xylene and ventilation facilities were detected and analyzed statistically. Results: It showed that the detection rate of xylene and formaldehyde was 82.1% (23/28) , and the detection rate of xylene C(STEL) in the two sampling posts was 14.3% (2/14) , the local suction device on each side and the control wind speed of the fume hood do not meet the national standards. Conclusion: It is necessary to strengthen the prevention and control of the occupational hazards in the Department of Pathology to prevent the occurrence of occupational diseases.

Complete mitochondrial genome of the whitefly Aleyrodes shizuokensis Kuwana (Hemiptera: Aleyrodidae), new record from Chinese mainland

The complete mitochondrial genome was determined for the whitefly Aleyrodes shizuokensis (Hemiptera: Aleyrodidae), the first record from Chinese mainland. The mitochondrial genome is 16,687 bp in length and contains 13 protein-coding genes (PCGs), 22 transfer RNAs, and two ribosomal RNAs. The overall base composition is 33.8% A, 47.0% T, 12.2% G, and 7.0% C. All PCGs start with ATN codon. COX1 ends with a T, and the other 12 PCGs use TAA or TAG as the stop codon. Gene arrangement of the 13 PCGs is identical to that of the giant whitefly Aleurodicus dugesii and greenhouse whitefly Trialeurodes vaporariorum. The resultant Bayesian inference and maximum-likelihood trees based on the sequence data of 13 PCGs support its close relationship with sugarcane whitefly Neomaskellia andropogonis.

[Management strategy of lung protection in patients with intra-abdominal infection]

Lung protection is important in the treatment of patients with intra-abdominal infection (IAI). This article focuses on the management strategy of lung protection in IAI patients. In the implementation of IAI individual respiratory protection, good humidification and chest physical therapy, nutritional support, strict balloon management, keeping a semi-supine position, and reducing the duration and depth of analgesia and sedation are helpful to maintain effective coughing capacity and prevent silent aspiration. It is also necessary to prevent ventilator-associated lung injury in mechanical ventilation, and implement strategies of small tidal volume, limited platform pressure, diaphragmatic protection and right heart protection ventilation in acute respiratory distress syndrome (ARDS). Respiratory mechanical indicators, including airway resistance, respiratory compliance, maximum inspiratory pressure (MIP), and airway closure pressure (P0.1) can be used in IAI patients receiving mechanical ventilation for individualized assessment and monitoring of respiratory functional status. Patients with IAI who have not been treated with mechanical ventilation can use simplified bedside lung function indicators, including forced vital capacity of inhalation and exhalation, maximum inspiratory pressure and exhalation pressure, as well as volume and rate of 1s. In pulmonary rehabilitation, the protection technique of the seven-word principle of humidification, turning, patting, coughing, expansion, blowing and mobilization are implemented.

Detachment in Fusion Plasmas with Symmetry Breaking Magnetic Perturbation Fields

Power exhaust from the bulk plasma is significantly altered by symmetry breaking magnetic perturbation fields, because these create direct connections (perturbed field lines) from the confined high temperature plasma to solid surfaces. The same amount of power is distributed among those new exhaust channels as for a symmetric magnetic configuration, which reduces the local upstream heat flux flowing down the perturbed field lines, thereby making access to detachment easier (i.e., at lower upstream density) for the divertor plasma near the location corresponding to the symmetric magnetic separatrix. However, the divertor plasma regions with connection to the bulk plasma are extended nonaxisymmetrically further outside, where significant heat loads occur, unlike in the symmetric configuration. The temperature remains high at those locations, which reduces the divertor plasma dissipation capacity, making the mitigation of heat loads more difficult to achieve.

[Application of risk assessment of dust occupational hazards during subway construction]

Objective: To identify the process nodes and types of dust existing during subway construction, evaluate the occupational health risk assessment, analyze the key control points, and provide technical basis for occupational health management. Methods: From August 2017 to December 2018, the field occupational health survey method was used to investigate the whole construction period of subway, and the occupational health risk assessment method was used to assess the degree of dust hazard, and the consistency of the assessment results of ICMM, UQ and MLSP methods were compared. Results: The dust in the operation site exists in multiple nodes of the construction cycle, and the operators were exposed to a variety of dust at the same time. Concrete workers and other jobs were key control posts. The risk level assessed by ICMM method was relatively higher than that by UQ method and MLSP method, the latter two results were relatively close. Conclusion: The three occupational health risk assessment methods are all suitable for the site risk assessment without occupational monitoring data, and UQ method has better applicability to the construction industry.

[Effects of double-catheter epidural analgesia by lidocaine injection respectively on the delivery outcomes and maternal-infant complications for persistent posterior or lateral occipital position of protracted active phase]

Objective: To evaluate the effect of dual-tube epidural segmental injection of lidocaine analgesia on the delivery outcome and maternal and infant complications of persistent posterior occipital position postpartum or lateral occipital position postpartum patients with protracted active phase. Methods: The full and single-term primiparas (n=216, 37 to 42 weeks gestation, 22 to 35 years) diagnosed as persistent posterior or lateral occipital position during the active period were selected from the Department of Obstetrics of Qingdao Municipal Hospital from January 2015 to October 2019. The subjects were randomly assigned into two groups: double-tube epidural block group (n=108) and single-tube epidural block group (n=108), 1% lidocaine was used for epidural analgesia respectively under ultrasound guidance. Senior midwife or obstetricians implement new partogram, and guide women to perform position management, and push or rotate the fetal head in a timely manner. Observation indicators: general condition, the use of non-pharmacological analgesic measures, analgesia related conditions and pain visual analogue scale (VAS) score, delivery-related indicator, cesarean section indication, anesthesia-related indicator, maternal and child complications. Results: (1) General condition: the age, weight, height, gestational age, the ratio of persistent lateral or posterior occipital position, cephalic score, and neonatal birth weight between the two groups of women were not statistically significant (all P>0.05). (2) The use of non-pharmacological analgesic measures: the women's Lamaze breathing method, Doula delivery companionship, percutaneous electrical stimulation, and other measures between two groups were compared, and there were not significant differences (all P>0.05). (3) Analgesia related conditions and VAS scores of women undergoing vaginal delivery: compared with the single-tube epidural block group (n=40), the second-partum time of the women in the double-tube epidural block group (n=59) was significantly shortened [(124±44) vs (86±33) minutes, P<0.01]; after 30 minutes of analgesia (4.4±0.5 vs 0.9±0.5, P<0.01), during forced labor in the second stage of labor (5.7±0.6 vs 1.3±0.4, P<0.01), the VAS scores of pain were also significantly reduced (P<0.01). (4) Labor-related indicators: compared with the single-tube epidural block group, the natural delivery rate (21.3% vs 49.1%) and the delivery experience satisfaction rate (51.9% vs 98.1%) of women in the double-tube epidural block group were significantly increased (all P<0.01), cesarean section rate (63.0% vs 45.4%), instrument assisted rate (15.7% vs 5.6%) decreased significantly (all P<0.05). (5) Cesarean section indications: compared with the single-tube epidural block group, the cesarean section rate caused by prolonged labor or protracted active phase of women in the double-tube epidural block group was significantly reduced (38.0% vs 22.2%； P<0.05), and the fetal distress, intrauterine infection, and social factors caused by cesarean section between the two groups were compared, while the differences were not statistically significant (all P>0.05).(6) Anesthesia related indexes: the block planes of the maternal upper tube administration in the double-tube epidural block group were mostly T7, T8, T9-L2 and L3,While,the block planes in the single-tube epidural block group were mostly T10, T11-S1, S2, S3, and the modified Bromage score were all 0. (7) Maternal and child complications: compared with the single-tube epidural block group, the postpartum hemorrhage rate (18.5% vs 7.4%), the perineal lateral cut rate (20.4% vs 5.6%), the neonatal asphyxia rate (12.0% vs 3.7%), ICU rate of transferred neonates (13.9% vs 4.6%) in the double-tube epidural block group were significantly reduced (all P<0.05). Soft birth canal injury rate, puerperal disease rate and neonatal birth rate between two groups were compared, and there were not statistically significant differences (all P>0.05). Conclusion: Dual-tube epidural segmental injection of lidocaine analgesia could increase the natural delivery rate of women with posterior occipital or lateral occipital position with active stagnation, reduce the rate of cesarean section and the rate of transvaginal instruments, and reduce the complications of mother and child.

[Time-series analysis on the relationship between ambient PM2.5 and daily outpatient visits due to allergic conjunctivitis among children in Shenzhen]

Objective: To explore the short-term effects of ambient PM_2.5 on the outpatient visits of allergic conjunctivitis among children in Shenzhen. Methods: It was a ecological study. Data on daily visits including date of visit, sex and age from children with allergic conjunctivitis were collected from Shenzhen Eye Hospital and Shenzhen Children's Hospital in 2018. Related data on air pollution (PM_2.5, PM₁₀, SO₂, NO₂, CO and O₃) and meteorology (atmospheric pressure, temperature and relative humidity) were also collected. Pearson correlation analysis was used for normal distribution data and Spearman rank correlation analysis was used for non-normal distribution data. Generalized additive model was used to estimate the impact of PM_2.5 pollution on allergic conjunctivitis outpatients and the lagging effects. Results: In 2018, there were 16 133 allergic conjunctivitis outpatients in the two hospitals. The maximum age was 18 years and the minimum age was 2 months. Males accounted for 49.3%. The daily average concentration of PM_2.5 was 22 (15, 31) μg/m³. Changes of the concentration of PM_2.5 had a positive correlation with the amount of allergic conjunctivitis visits, and the Spearman correlation coefficient was 0.150 (P=0.004). The single pollutant model showed that the strongest effect appeared at 3 days (RR=1.111， 95%CI:1.071-1.152). A 10 μg/m³ increase of PM_2.5 would result in an excessive number of allergic conjunctivitis outpatients as much as 11.112% (95%CI：7.011%-15.212%). In the multiple air pollutants models, after the introduction of NO₂, O₃ and CO, the concentration of PM_2.5 showed an enhanced effect on the number of hospital visits due to allergic conjunctivitis on the same day, and the difference was statistically significant (P<0.05). Conclusion: Changes of the concentration of PM_{2.5 h}ad a positive correlation with daily outpatient visits of allergic conjunctivitis among children in Shenzhen. (Chin J Ophthalmol, 2020, 56: 608-614).

[Investigation on the health status of workers exposed to benzene in one province]

Objective: To explore the health status of occupational benzene exposure workers, and to provide a scientific basis for the development of reasonable health monitoring and effective protective measures. Methods: In March 2019, the occupational health surveillance data were collected including blood pressure, electrocardiogram, blood routine, urine routine, liver function, etc of 7810 benzene contact workers in 150 enterprises in Jiangxi Province in 2017, to analyze and assess their health status. Results: Among the 7810 benzene workers, there were 5451 males and 2359 females; the average age was (40.5±9.9) years; and the median benzene working age was 3.5 years. The detection rate of hypertension was 17.0% (734/4317) , the abnormal rate of urine routine was 15.7% (1227/7810) , the abnormal rate of liver function was 8.6% (356/4147) , and the abnormal rate of electrocardiogram was 12.3%(963/7810). The detection rates of low count number of leukocytes, platelets, neutrophils and occupational contraindications were 4.6%(360/7810) , 1.4%(108/7810) , 4.2%(330/7810) and 1.4%(110/7810) , respectively. The detection rates of low count number of leukocytes, platelets and neutrophils in female were all higher than those in male (P<0.05). The detection rates of low count number of platelets, neutropenia and occupational contraindications increased with age and working age (P<0.05 ). There were significant differences in the detection rates of low count number of leukocytes, platelets, neutrophils and occupational contraindications among benzene workers in different economic types (P<0.05) , and the highest among foreign companies, followed by private enterprise. There were statistically significant differences in the detection rates of low count number of platelets, neutrophils and occupational contraindications in benzene workers of different enterprise sizes (P<0.05) , and the highest was found in micro enterprises, followed by small enterprises. Conclusion: In 2017, the occupational health status of workers exposed to benzene in Jiangxi province is not optimistic. It is necessary to strengthen the occupational health supervision of small and micro-sized enterprises, foreign enterprises and private enterprises, take the initiative to improve health surveillance, and effectively protect the physical and mental health of workers.

Localization and Quantification of Begomoviruses in Whitefly Tissues by Immunofluorescence and Quantitative PCR

Begomoviruses (genus Begomovirus, family Geminiviridae) are transmitted by whiteflies of the Bemisia tabaci complex in a persistent, circulative manner. Considering the extensive damage caused by begomoviruses to crop production worldwide, it is imperative to understand the interaction between begomoviruses and their whitefly vector. To do so, localization and quantification of the virus in the vector tissues is crucial. Here, using tomato yellow leaf curl virus (TYLCV) as an example, we describe a detailed protocol to localize begomoviruses in whitefly midguts, primary salivary glands, and ovaries by immunofluorescence. The method is based on the use of specific antibodies against a virus coat protein, dye-labeled secondary antibodies, and a confocal microscope. The protocol can also be used to colocalize begomoviral and whitefly proteins. We further describe a protocol for the quantification of TYLCV in whitefly midguts, primary salivary glands, hemolymph, and ovaries by quantitative PCR (qPCR). Using primers specifically designed for TYLCV, the protocols for quantification allow the comparison of the amount of TYLCV in different tissues of the whitefly. The described protocol is potentially useful for the quantification of begomoviruses in the body of a whitefly and a virus-infected plant. These protocols can be used to analyze the circulation pathway of begomoviruses in the whitefly or as a complement to other methods to study whitefly-begomovirus interactions.

A newly recorded Rickettsia of the Torix group is a recent intruder and an endosymbiont in the whitefly Bemisia tabaci

The bacterium Rickettsia is found widely in phytophagous insects and often exerts profound effects on the phenotype and fitness of its hosts. Here, we decrypt a new, independent, phylogenetically ancient Torix Rickettsia endosymbiont found constantly in a laboratory line of an economically important insect Asia II 7, a putative species of the Bemisia tabaci whitefly complex (Hemiptera: Aleyrodidae), and occasionally in field whitefly populations. This new Rickettsia distributes throughout the body of its whitefly host. Genetically, compared to Rickettsia_bellii_MEAM1 found earlier in whiteflies, the new Rickettsia species has more gene families and pathways, which may be important factors in shaping specific symbiotic relationships. We propose the name 'Candidatus Rickettsia_Torix_Bemisia_tabaci (RiTBt)' for this new endosymbiont associated with whiteflies. Comparative genomic analyses indicate that RiTBi may be a relatively recent intruder in whiteflies given its low abundance in the field and relatively larger genome compared to Rickettsia_bellii_MEAM1.

[A study of social assistance for patients with occupational diseases]

Since the reform and opening up, a large number of migrant workers to enter into the mining enterprises of the town, due to poor working conditions and lack of awareness of labor protection, a large number of workers at that time were diagnosed with occupational diseases such as pneumoconiosis, the lack of effective treatment and compensation mechanisms, it faces many difficulties of life, health care, employment and marriage, becoming more vulnerable, need access to national and social support and assistance. Currently, the patient's occupation of social assistance there are some flaws, and for the growing demand for professional rescue patients, China is still not established specifically for the social assistance system of the patient career, but also lack of systematic research. The paper combing through social assistance in the form and content of the existing occupation for patients and found deficiencies and problems of the current social assistance vocational patient exists, and proposed a framework for the establishment of vocational social assistance system of the patient, specific measures and means.

[Analysis on the consciousness of the cancer early detection and its influencing factors among urban residents in China from 2015 to 2017]

Objective: To understand the consciousness of the cancer early detection among urban residents and identify the influencing factors from 2015 to 2017. Methods: A cross-sectional survey was conducted in 16 provinces covered by the Cancer Screening Program in Urban China from 2015 to 2017. A total of 32 257 local residents aged ≥18 years old who could understand the investigation procedure were included in the study by using the cluster sampling method and convenient sampling method. All local residents were categorized into four groups, which contained 15 524 community residents, 8 016 cancer risk assessment/screening population, 2 289 cancer patients and 6 428 occupational population, respectively. Self-designed questionnaires were used to collect population, socioeconomic indicators, self-cancer risk assessment, regular participation in physical examination and other information. The multivariate logistic regression model was used to identify the factors of people who had not regularly participated in the regular physical examination in the past five years. Results: The self-assessment results of 32 357 residents showed that there were 27.54% (8 882) of total study population with self-reported cancer risk, 45.48% (14 671) without cancer risk and 26.98% (8 704) with unclear judgement on their own cancer risk. Among population with cancer risk, 79.84% (7 091) considered physical examination accounted. In the past five years, there were 21 105 (65.43%) residents participated in regular physical examination and 11 148 (34.56%) participated in non-scheduled one, respectively. The multivariate logistic regression analysis showed that compared with unmarried and western region residents, divorced, middle and eastern region residents had a stronger consciousness to participate in the regular physical examination (P<0.05). Compare with residents with annual household income less than 20 000 CNY in 2014, cancer risk assessment/screening intervention population, and self-assessment with cancer risk, residents with annual household income between 20 000 CNY and 59 000 CNY in 2014, occupational population, community residents, cancer patients, self-reported cancer-free risk, and self-assessment with unclear judgement of cancer risk were less likely to participate in the regular physical examination (all P values <0.05). Conclusion: From 2015 to 2017, the Chinese urban residents had a acceptable consciousness of the cancer early detection. The marital status, annual household income, population group and self-assessment of cancer risk were related to the consciousness of the cancer early detection of people who had not participated in the regular physical examination in the past five years.

[Analysis on the demand, access and related factors of cancer prevention and treatment knowledge among urban residents in China from 2015 to 2017]

Objective: To investigate the demand and access to the cancer prevention and treatment knowledge and related factors among urban residents in China from 2015 to 2017. Methods: A cross-sectional survey was conducted in 16 provinces covered by the Cancer Screening Program in Urban China from 2015 to 2017. A total of 32 257 local residents aged ≥18 years old who could understand the investigation procedure were included in the study by using the cluster sampling method and convenient sampling method. All local residents were categorized into four groups, which contained 15 524 community residents, 8 016 cancer risk assessment/screening population, 2 289 cancer patients and 6 428 occupational population, respectively. The self-designed questionnaire was used to collect the information of general demographic characteristics, the demand and access to cancer prevention and treatment knowledge, and the influencing factors of the attitude. The Chi-square test was used to analyze the difference of the demand of the cancer prevention knowledge among different groups and the corresponding factors of the cancer prevention and treatment knowledge were analyzed by using the logistic regression model. Results: The proportion of residents who need the cancer prevention and treatment knowledge was 79.5%. The demand rate of the inducement, symptom and diagnosis methods of cancer in the occupational population was highest, about 66.8%, 71.0% and 20.8%, respectively. The demand rate of treatment methods and cost in current cancer patients was the highest, about the 45.9% and 21.9%, respectively. The top three sources to acquire the cancer prevention and treatment knowledge were "broadcast or television" (69.5%), "books, newspapers, posters or brochures" (44.7%) and "family and friends" (33.8%). The multivariate analysis showed that compared with public institution personnel/civil servants, unmarried/cohabiting/divorced/widowed and others, annual household income less than 20 000 CNY, from the eastern region, people without cancer diagnosis and people with self-assessment of cancer risk, the demand rate of cancer prevention and treatment knowledge was higher in enterprise personnel/workers, married, annual household income between 60 000 CNY and 150 000 CNY, from the central region, people with cancer and people with unclear cancer risk (all P values <0.05). Conclusion: There was a high demand for the cancer prevention and treatment knowledge among urban residents in China from 2015 to 2017. The main access to the knowledge is from the radio or television. The occupation, marital status, annual household income, residential region, health status and risk of disease were the main factors of the demand of the cancer prevention and treatment knowledge.

[Study on the health literacy and related factors of the cancer prevention consciousness among urban residents in China from 2015 to 2017]

Objective: To understand the health literacy and relevant factors of cancer prevention consciousness in Chinese urban residents from 2015 to 2017. Methods: A cross-sectional survey was conducted in 16 provinces covered by the Cancer Screening Program in Urban China from 2015 to 2017. A total of 32 257 local residents aged ≥18 years old who could understand the investigation procedure were included in the study by using the cluster sampling method and convenient sampling method. All local residents were categorized into four groups, which contained 15 524 community residents, 8 016 cancer risk assessment/screening population, 2 289 cancer patients and 6 428 occupational population, respectively. The self-designed questionnaire was used to collect the information of demographic characteristics and cancer prevention consciousness focusing on nine common risk factors, including smoking, alcohol, fiber food, food in hot temperature or pickled food, chewing betel nut, helicobacter pylori, moldy food, hepatitis B infection, estrogen, and exercise. The logistic regression model was adopted to identify the influencing factors. Results: The overall health literacy of the cancer prevention consciousness was 77.4% (24 980 participants), with 77.4% (12 018 participants), 79.9% (6 406 participants), 77.2% (1 766 participants) and 74.5% (4 709 participants) in each group (P<0.001). The correct response rates for nine risk factors ranged from 55.2% to 93.0%. The multivariate logistic regression analysis showed that compared with community residents, people with primary school level education or below, and the number of people living together in the family <3, the cancer risk assessment/screening intervention population, cancer patients, those with junior high school level educationor above and the number of people living in the family ≥3 had better health literacy of the cancer prevention consciousness (all P values <0.05). Compared with females, 39 years old and below, government-affiliated institutions or civil servants, from the eastern region, males, older than 40 years, company or enterprise employees, and from the middle or western region had worse health literacy of the cancer prevention consciousness (all P values <0.05). Conclusion: The health literacy of the cancer prevention consciousness in Chinese urban residents should be improved. The cancer screening intervention, gender, age, education, occupation, the number of people co-living in the family, and residential region were associated with the health literacy of the cancer prevention consciousness.

[Analysis on the health literacy of the cancer prevention and treatment and its related factors among urban residents in China from 2015 to 2017]

Objective: To understand the health literacy of the cancer prevention and treatment among urban residents of China, and explore the related factors. Methods: A cross-sectional survey was conducted in 16 provinces covered by the Cancer Screening Program in Urban China (CanSPUC) from 2015 to 2017. A total of 32 257 local residents aged ≥18 years old who could understand the investigation procedure were included in the study by using the cluster sampling method and convenient sampling method. All local residents were categorized into four groups, which contained 15 524 community residents, 8 016 cancer risk assessment/screening population, 2 289 cancer patients and 6 428 occupational population, respectively. The health literacy of the cancer prevention, early discovery, early diagnosis, early treatment and the demands of cancer prevention and treatment knowledge was analyzed. The level of health literacy among different groups were calculated and compared. The binary logistic regression model was used to analyze the influencing factors of the health literacy of the cancer prevention and treatment. Results: The level of health literacy of the cancer prevention and treatment was 56.97% among all study population; in each group it was 55.01% for community residents, 59.08% for cancer risk assessment/screening population, 61.99% for cancer patients and 57.31% for occupational population, respectively (P<0.001). The level of health literacy of the cancer prevention and treatment of residents aged 50 to 69 years old, other occupational groups, unmarried, the central and western region residents and the group with unclear self-assessment of cancer risk was significantly lower than that of residents younger than 40 years old, personnel of public institutions/civil servants, married, the eastern region residents and the group whose self-assessment without cancer risk (P<0.05) . The level of health literacy of cancer prevention and treatment of females, people who went to high school or over, cancer risk assessment/screening population, cancer patients and occupational population was significantly higher than that of males, people who had an education level of primary school or below and community residents (P<0.05) . Conclusion: The health literacy of the cancer prevention and treatment of urban residents in China was relatively high, but there was still room for improvement. Gender, age, educational level, occupation, region, marital status, self-assessment of cancer risk, and type of respondents were the key influencing factors of the health literacy of the cancer prevention and treatment. Male, 50-69 years old, lower educational level, central and western regions, unclear cancer risk self-assessment, and without specific environmental exposure to cancer prevention and treatment knowledge or related risk factors were the characteristics of the key intervention group of the health literacy of the cancer prevention and treatment.

[Analysis on the consciousness of the early cancer treatment and its influencing factors among urban residents in China from 2015 to 2017]

Objective: To understand the consciousness of the cancer early treatment and its demographic and socioeconomic factors. Methods: A cross-sectional survey was conducted in 16 provinces covered by the Cancer Screening Program in Urban China (CanSPUC) from 2015 to 2017. A total of 32 257 local residents aged ≥18 years old who could understand the investigation procedure were included in the study by using the cluster sampling method and convenient sampling method. All local residents were categorized into four groups, which contained 15 524 community residents, 8 016 cancer risk assessment/screening population, 2 289 cancer patients and 6 428 occupational population, respectively. The questionnaire collected personal information, the consciousness of the cancer early treatment and relevant factors. The Chi square test was used to compare the difference between the consciousness of the cancer early treatment and relevant factors among the four groups. The logistic regression model was used to analyze the influencing factors related to the consciousness of the cancer early treatment. Results: With the assumption of being diagnosed as precancer or cancer, 89.97% of community residents, 91.84% of cancer risk assessment/screening population, 93.00% of cancer patients and 91.52% of occupational population would accept active treatments (P<0.001). If the immediate family members were diagnosed as precancer or cancer, people who would encourage their family members to receive early treatment in the four groups accounted for 91.96%, 91.94%, 92.44% and 91.55%, respectively (P<0.001). The company employees, annual household income with 40 000 yuan and more and other three groups had a relatively better consciousness of the cancer early treatment (P<0.05). Male, widowed, unemployed and from the central and western regions had a relatively worse consciousness of the cancer early treatment (P<0.05). Conclusion: Residents in urban China participants had a good consciousness of the cancer early treatment. The marital status, occupation, annual household income and residential regions were major factors related to the consciousness of the cancer early treatment.