Ammonia stripping by in situ biogas self-circulation to upgrade continuous thermophilic and mesophilic digestion of hydrothermal high-solid sludge.

High-solid anaerobic digestion of hydrothermal sewage sludge has been developed. In order to upgrade the process by focusing on ammonia inhibition, a simply-equipped stripping system without additional alkali or heat supply was introduced by in situ biogas self-circulation. As the determined limit of total ammonia nitrogen at 1500 mg/L and 1000 mg/L for the mesophilic (MAD) and thermophilic anaerobic digestion (TAD) respectively and stripping rate at 5 L/min, continuous MAD and TAD was conducted in parallel. The stripping system successfully polished up the ammonia inhibition, and methanogenic capability of the TAD was promoted to approximately 90.0 % of the potential. Intermittent stripping mode proved usable. More frequent stripping was inevitable for the TAD as compared to the MAD. Hydraulic retention time below 20 d resulted in failure of the stripping mode due to rapid ammonia generation. Overall, this technology was practical in upgrading high-solid sludge digestion by effective ammonia control.

Lower limit characterization of segregation degree for large-size low-alloy steel.

Based on the original position statistic distribution analysis technique, the characterization method of segregation for large-size metal materials gives significant guidance to the research of material properties and production. However, random errors are inevitably brought into the calculation of segregation degree for materials characterization by the Spark Mapping Analysis for Large Sample (SMALS) technique, resulting in a misguide of the segregation degree. In this paper, we present the lower limit of segregation degree (Ds(L)) method to distinguish the random error from metal material segregation for large-size samples over the SMALS method. The random error of standard material in the 95% confidence interval was utilized as Ds(L) and the method has been applied for macro-segregation quantitative analysis. The precision correlation between Spark Atomic Emission Spectrometry (Spark-AES) and SMALS was established. Furthermore, the functional relationship between the Ds(L) and element content C can be obtained in the SMALS method. The Ds(L) method as the criterion can be used to not only characterize the minimum limit of the segregation degree but also the segregation existence for large-size samples. Applying to low-alloy steel can illustrate the effective performance of the Ds(L) method. Results on both spark mapping analysis and Spark-AES verify the substantial consistency.

[Intervention of modified Shenling Baizhu San on peritoneal fibrosis induced by peritoneal dialysate with different sugar concentration in rats].

OBJECTIVE: To investigate the effect of modified Shenling Baizhu San on the pathological changes and extracellular matrix (ECM) in rats with peritoneal fibrosis induced by peritoneal dialysate fluid (PDF) with different sugar concentration and its mechanism. METHODS: Seventy male Sprague-Dawley (SD) rats were randomly divided into control group, different sugar content PDF model groups and corresponding traditional Chinese medicine intervention groups, with 10 rats in each group. Peritoneal fibrosis model was reproduced by intraperitoneal injection of 100 mL×kg-1×d-1 PDF containing 1.5%, 2.5% and 4.25% sugar once a day for 8 weeks. The rats in the control group were given the same amount of normal saline. The rats in the traditional Chinese medicine intervention groups were treated with gavage of 10 mL/kg of modified Shenling Baizhu San (containing 2.014 g crude drug per liter) immediately after modeling. The PDF model groups and the control group were given the same amount of normal saline by gavage. After 8 weeks, the peritoneal ultrafiltration volume of rats in each group was measured. The peritoneal tissues were collected and stained with hematoxylin-eosin (HE), and the structural changes and thickness of the parietal peritoneum were observed under a light microscope. After Masson staining, the deposition of collagen fibers was observed under a light microscope. Western blotting was used to detect the protein expressions of E-cadherin, α-smooth muscle actin (α-SMA) and Vimentin, the main components of ECM in parietal peritoneum. The positive expressions of matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), and transforming growth factor-ß1 (TGF-ß1) were detected by immunohistochemical staining. RESULTS: Compared with the control group, PDF with different sugar contents could induce peritoneal fibrosis in rats, and the degree of fibrosis was gradually aggravated with the increase of sugar content, which was manifested as peritoneal thickening, increased collagen fiber deposition, decreased peritoneal ultrafiltration volume, down-regulated expressions of E-cadherin and MMP-9 in peritoneal tissue, and up-regulated expressions of α-SMA, Vimentin, TIMP-1 and TGF-ß1, and the pathological changes and ECM accumulation in peritoneal tissues were more serious in 4.25% PDF model group. After the intervention of modified Shenling Baizhu San, compared with the corresponding PDF model groups, the peritoneal fibrosis of rats was improved to varying degrees, and the effect of the 4.25% PDF+traditional Chinese medicine intervention group was more significant, the parietal peritoneum was significantly thinner (µm: 101.86±16.01 vs. 140.65±10.13, P < 0.05), collagen fiber deposition was significantly reduced, peritoneal ultrafiltration volume was significantly increased (mL: -0.01±3.45 vs. -3.53±1.84, P < 0.05), the expressions of E-cadherin and MMP-9 in peritoneal tissues were significantly up-regulated [E-cadherin protein (E-cadherin/ß-actin): 0.84±0.08 vs. 0.28±0.05, MMP-9 (A value): 0.60±0.15 vs. 0.37±0.01, both P < 0.05], and the expressions of α-SMA, Vimentin, TIMP-1 and TGF-ß1 were significantly down-regulated [α-SMA protein (α-SMA/ß-actin): 0.36±0.08 vs. 1.05±0.09, Vimentin protein (Vimentin/ß-actin): 0.53±0.07 vs. 1.19±0.04, TIMP-1 (A value): 0.49±0.06 vs. 0.87±0.02, TGF-ß1 (A value): 0.67±0.04 vs. 0.89±0.10, all P < 0.05]. CONCLUSIONS: The degree of peritoneal fibrosis gradually increased with the increase of PDF sugar content in rats. Modified Shenling Baizhu San can improve peritoneal fibrosis induced by PDF with different sugar contents in rats, and the mechanism is related to the changes in the expression of fibrosis markers and ECM accumulation.

Rigid Gas-Permeable Contact Lens for Visual Rehabilitation in Children Younger Than 12 Years With Penetrative Ocular Trauma.

OBJECTIVES: To observe the clinical outcomes of visual rehabilitation using rigid gas-permeable contact lenses (RGPCLs) after penetrative ocular trauma in children younger than 12 years in China. METHODS: Patients younger than 12 years with penetrative ocular trauma fitted with an RGPCL for visual rehabilitation from 2017 to 2021 were included. In the case cohort, the best-corrected visual acuity (BCVA) with spectacles was measured when the RGPCL was fitted, and the initial BCVA with RGPCL, and the BCVA at the last visit were compared. RESULTS: Fifteen patients, aged 4 to 12 (mean 8.0±2.7) years, who wore an RGPCL for 7 to 53 (mean 20.3±15.7) months, were included. The BCVA was log of minimal angle of resolution 0.4 (0.2-0.7) with spectacles and 0.1 (0.1-0.2) for RGPCL at the initial visit, and 0.0 (0.0-0.1) for BCVA at the last visit, with a statistically significant difference between the three comparisons ( P <0.001). Six of the 15 (40%) children abandoned wearing RGPCL because of discomfort and lens rejection (n=3, 50%), lens loss and inability to replace broken lens because of travel distances and epidemics (n=2, 33%), and cost (n=1, 17%). CONCLUSIONS: Although application is complicated and initial wearing comfort is poor, an RGPCL is still a beneficial, safe tool for postoperative visual rehabilitation in children with open ocular trauma.

Diversity of Rickettsiales bacteria in five species of ticks collected from Jinzhai County, Anhui Province, China in 2021-2022.

The order Rickettsiales in the class Alphaproteobacteria comprises vector-borne pathogens of both medical and veterinary importance. Ticks, as a group, are second only to mosquitoes as vectors of pathogens to humans, playing a critical role in the transmission of rickettsiosis. In the present study, 880 ticks collected from Jinzhai County, Lu'an City, Anhui Province, China in 2021-2022 were identified as belonging to five species from three genera. DNA extracted from individual ticks was examined using nested polymerase chain reaction targeting the 16S rRNA gene (rrs), and the gene fragments amplified were sequenced to detect and identify Rickettsiales bacteria in the ticks. For further identification, the rrs-positive tick samples were further amplified by PCR targeting the gltA and groEL gene and sequenced. As a result, 13 Rickettsiales species belonging to the genera Rickettsia, Anaplasma, and Ehrlichia were detected, including three tentative species of Ehrlichia. Our results reveal the extensive diversity of Rickettsiales bacteria in ticks from Jinzhai County, Anhui Province. There, emerging rickettsial species may be pathogenic and cause under-recognized diseases. Detection of several pathogens in ticks that are closely related to human diseases may indicate a potential risk of infection in humans. Therefore, additional studies to assess the potential public health risks of the Rickettsiales pathogens identified in the present study are warranted.

VWM-based bias in conscious access can be extended to a new sandwich masking task and real-life stimuli.

Previous studies using breaking continuous flash suppression observed that the content of visual working memory (VWM) influences the priority for accessing visual awareness. However, most studies have used simple stimuli, whereas real-life objects are typically more meaningful and contain more perceptual information than simple objects. In this study, we intermixed a delayed match-to-sample task to manipulate the content of VWM, and a breaking repeated masking suppression (b-RMS) task to investigate whether this memory-based effect in conscious access can be extended to a new sandwich masking task and real-life stimuli. The results revealed that memory-congruent objects broke RMS faster than incongruent objects for both simple and real-life objects. Specifically, for simple objects, color-matching targets broke RMS faster than color-mismatching targets, whereas state-matching targets broke RMS faster than state-mismatching targets for real-life objects. These results suggest that the faster detection of VWM-matching over VWM mismatching stimuli-which has been mostly studied using only one type of task (b-CFS) and stimulus (colored shapes)-extends to (1) yet another masking technique (b-RMS) and to (2) a novel stimulus type (real-life objects), providing evidence that memory-based biases in conscious access are a ubiquitous phenomenon.

Comparative analysis of pre- and postmenopausal endometrial cancer in 216 patients.

Background: Endometrial carcinoma (EC) is one of the most common gynecological malignancies and has become more prevalent in recent decades. The clinical manifestations and characteristics of EC in premenopausal and postmenopausal women differ and present with distinct pathological stages and subtypes of EC. Surgery remains the principal therapeutic approach, but the postoperative prognosis is largely affected by the pathological state. Methods: A retrospective study was conducted on 216 patients with EC who were hospitalized from August 2008 to August 2019 in Wuhan Union Hospital. The patients were divided into 2 groups based on the pre- or postmenopausal occurrence of EC. The general clinical characteristics, intraoperative situation, clinicopathological data, and postoperative outcomes of the 2 groups were compared. Results: Patients with premenopausal EC had earlier menarche, a higher incidence of primary infertility and anemia, and fewer pregnancies and deliveries. Patients with postmenopausal EC were older and often had hyperlipidemia and diabetes. Additionally, patients who were postmenopausal had worse tumor pathological gradings, more severe muscular invasion, and a higher rate of lymphatic metastasis. These factors led to a higher demand for postoperative radiotherapy in patients but a lower survival rate. Conclusions: Generally, premenopausal EC differs from postmenopausal EC: the latter is more malignant and has a worse prognosis.

Effectiveness of a booster dose of COVID-19 vaccines during an outbreak of SARS-CoV-2 Omicron BA.2.2 in China: A case-control study.

Real-world evidence on the effectiveness of COVID-19 vaccines marketed in China against the Omicron BA.2.2 variant remains scarce. A case-control study was conducted to estimate the vaccine effectiveness (VE) of COVID-19 vaccines marketed in China (inactivated vaccines, an Ad5-nCoV vaccine, and a recombinant protein vaccine). There were 414 cases infected with SARS-CoV-2 and 828 close contacts whose test results were consecutively negative as controls during the outbreak of the Omicron variant in Lu'an City, Anhui Province, China, in April 2022. The overall adjusted VE against Omicron BA.2.2 variant infection in the vaccinated group with any COVID-19 vaccine was 35.0% (95% CI: -9.1-61.3%), whereas the adjusted VE for booster vaccination was 51.6% (95% CI: 15.2-72.4%). Subgroup analysis showed that the overall adjusted VE of the Ad5-nCoV vaccine (65.8%, 95% CI: 12.8-86.6%) during the outbreak while any dose of inactivated vaccines and recombinant protein vaccine offered no protection. The adjusted VE of three-dose inactivated vaccines was 48.0% (95% CI: 8.0-70.6%), and the two-dose Ad5-nCoV vaccine was 62.9% (95% CI: 1.8-86%). There is no protection from a three-dose recombinant protein vaccine. COVID-19 vaccines offered 46.8% (95% CI: 9.5-68.7%) protection from infection within six months. There were statistically significant differences between the VEs of heterologous booster (VE = 76.4%, 95% CI: 14.3-93.5%) and homologous booster vaccination (VE = 51.8%, 95% CI: 9.6-74.3%) (P = .036). Booster vaccination of COVID-19 vaccines offered more protection than full vaccination. A booster vaccination campaign for a booster dose after three doses of a recombinant protein vaccine must be urgently conducted.

Excess methane production and operation stability for anaerobic digestion of oily food waste controlled by mixing intensity: Focusing on heterogeneity of long chain fatty acids.

Long chain fatty acids (LCFAs) are the key intermediate of anaerobic digestion of oily food waste, not completely soluble in a water-dominant anaerobic system due to their long hydrocarbon chains with hydrophobic property. Their effective concentration affects release of high methanogenic potential and system stability. A long-term continuous anaerobic digestion of oily food waste demonstrated excess methane production of even more than feedstock in an anaerobic continuous stirred tank reactor (CSTR). Assuming feedstock COD at 100%, approximately 120% of COD as methane could be achieved. Oil floating and crystallization with Ca salt resulting from the distribution heterogeneity of LCFAs in the CSTR were found responsible for the excess methane production. Moreover, slow conversion and accumulation of saturated LCFAs with relatively lower solubility played an important role as well. Compared with unsaturated oleic (C18:1) and linoleic acids (C18:2), around twice slower methane production rate and longer lag time could be observed for those saturated LCFAs. Mixing intensity was proved to be a critical controlling factor for methanogenesis and stability possibly by affecting interaction between oil/LCFAs and anaerobes to change effective lipid loading.

Management of an emergency sample collection team under the setting of whole-community severe acute respiratory syndrome coronavirus 2 nucleic acid testing.

BACKGROUND: During the coronavirus disease 2019 pandemic, a nucleic acid test is frequently conducted to identify positive cases. Compared with a hospital-based strategy, whole-community nucleic acid testing displays a unique advantage in rapid screening of a massive population. Yet a management plan to ensure ample and contamination-free sample collection is lacking.The objective of the current study was to establish an efficient operational mode of whole-community nucleic acid testing by management of a sample collection team and to provide a reference for joint prevention work to contain the spread of severe acute respiratory syndrome coronavirus 2. METHODS: The efficient operation of nucleic acid testing within the community was implemented by urgent setting up of sample collection teams, efficient allocation of medical supplies, optimization of management procedures and coordination among multiple working departments. RESULTS: A total of 21 585 nucleic acid samples were collected within 3 d, while no one was missed or experienced a cross infection. No falls, heatstroke, disputes or other adverse events occurred. CONCLUSIONS: Under the emergency setting of nucleic acid testing of a large population, a management system with orderly organization, clear division of responsibilities and standardized operational procedures should be formulated.

A comparative study of the clinical characteristics of spotted fever and severe fever with thrombocytopenia syndrome / 中国热带医学

@#Abstract: Objective To investigate the differences in epidemiological and clinical characteristics of patients with spotted fever (SF) and severe fever with thrombocytopenia syndrome (SFTS). Methods A total of 86 patients with SF and 113 patients with SFTS who were laboratory-confirmed in the second-level and above hospitals in Lu'an City from January 2017 to January 2022 were selected. The basic data, epidemiological history, clinical data and laboratory test results of the two diseases were retrospectively analyzed for comparison. Results The proportion of male in SF group was 32.56% (28/86), and the proportion of male in SFTS group was 53.98% (61/113), the difference was statistically significant (χ2=9.067, P<0.01). The proportions of abdominal pain and diarrhea in the SF group were (3.49%, 3/83) and (21.24%, 24/113), which were significantly lower than corresponding (6.98%, 6/86) and (46.90%, 53/113) in the SFTS group (χ2=13.121, 37.322, P<0.01). The incidences of rash and eschar in SF group were 95.35% (82/86) and 20.93% (18/86), which were significantly higher than corresponding 1.77% (2/113) and 0.88% (1/113) in SFTS group (χ2=175.311, 22.721, P<0.01). The levels of leukocytes, platelets and C-reactive protein in the SF group were significantly higher than those in the SFTS group, and the levels of transaminase, lactate dehydrogenase and D-dimer were significantly lower than those in the SFTS group, and the differences were statistically significant (all P<0.05). Conclusions The rash and inflammatory reaction are more obvious in SF patients, while the liver function, myocardial function and coagulation function are significantly impaired in SFTS patients.

The impact of self-compassionate mindfulness on online learning behavioral engagement of international students during COVID-19: Positive emotion and self-improvement motivation as mediators.

Focusing on the domain of self-compassion, this study explored the promotion mechanism of online learning behavioral engagement (OLBE) of international students in China under COVID-19. Positive emotion and self-improvement motivation were selected as mediators. Participants were 606 international students from 8 countries who were studying online in their own countries due to the international travel restriction of COVID-19. Results showed positive emotion and self-improvement motivation completely mediated self-compassionate mindfulness (SCM) and OLBE of international students. Positive emotion and self-improvement partially mediated SCM and OLBE of international students respectively. Students with higher SCM engage with online learning more in that they possess more positive emotion and self-improvement motivation. This study suggested that SCM may facilitate OLBE via positive emotion and effective self-improvement motivation.

Biological Activities Underlying the Therapeutic Effect of Quercetin on Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is a chronic autoimmune disorder stemming from unrestrained immune activation and subsequent destruction of colon tissue. Genetic susceptibility, microbiota remodeling, and environmental cues are involved in IBD pathogenesis. Up to now, there are limited treatment options for IBD, so better therapies for IBD are eagerly needed. The therapeutic effects of naturally occurring compounds have been extensively investigated, among which quercetin becomes an attractive candidate owing to its unique biochemical properties. To facilitate the clinical translation of quercetin, we aimed to get a comprehensive understanding of the cellular and molecular mechanisms underlying the anti-IBD role of quercetin. We summarized that quercetin exerts the anti-IBD effect through consolidating the intestinal mucosal barrier, enhancing the diversity of colonic microbiota, restoring local immune homeostasis, and restraining the oxidative stress response. We also delineated the effect of quercetin on gut microbiome and discussed the potential side effects of quercetin administration. Besides, quercetin could serve as a prodrug, and the bioavailability of quercetin is improved through chemical modifications or the utilization of effective drug delivery systems. Altogether, these lines of evidence hint the feasibility of quercetin as a candidate compound for IBD treatment.

Viability of recuperative thickening in upgrading thermophilic and mesophilic anaerobic digestion of hydrothermal high-solid sludge.

Recuperative thickening (RT) process was introduced to further upgrade anaerobic digestion of hydrothermal high-solid sludge. Continuous mesophilic (MD-R) and thermophilic (TD-R) digestion with RT (MD-R) were operated synchronously, with corresponding single digestion without RT as controls, namely MD and TD. The MD-R and TD-R increased biogas production rates by 22.8% and 11.0%, and achieved 16.6% and 9.7% higher volatile solids reductions, respectively. The improved performance was partly attributed to increased hydrolysis rate, with 11.2% and 7.4% higher for the MD-R and TD-R than the controls, respectively. The RT increased the numbers of total archaea in the mesophilic and thermophilic systems by 844% and 108%, and the numbers of dominant archaea by 50.4% and 38.1%, respectively, which promoted the degradation of organic matter and the production of biogas. Thus, RT is applicable to further upgrade digesting high-solid sludge.

Anaplasma bovis Infection in Fever and Thrombocytopenia Patients - Anhui Province, China, 2021.

What is already known about this topic?: The genusAnaplasma contains seven recognized bacterial species, mainly transmitted by tick bites. The two species, A. phagocytophilum and A. capra, are known commonly to cause diseases in humans. What is added by this report?: Anaplasma bovis was initially thought to be only an animal agent until the first patient case was reported in 2019. This study investigated another two patients who became sick within one month in the same township and were infected with A. bovis in Anhui Province. What are the implications for public health practice?: This study suggested that more A. bovis-infected patients may exist in this area and that patients with anaplasmosis require an early and specific diagnosis.

Finding meaning in "wrong responses": The multiple object-awareness paradigm shows that visual awareness is probabilistic.

Visual information that observers perceive and remember at any given moment guides behavior in daily life. However, binary alternative-forced choice responses, often used in visual research, limit the report of the visual information that observers perceive and remember. We used a new multiple object-awareness paradigm where observers can use multiple clicks to find a target. We calculated visual awareness capacity based on the first-attempt accuracy and the total number of clicks, respectively. Results showed that the capacity estimated by the clicks in guessing from N was significantly greater than that estimated by the first-attempt accuracy. Further, analysis found that if observers could not locate the target in their first attempt, they were more likely to click closer to the target or on stimuli that matched its color. In addition, we found that even when observers used the same number of clicks to find a target (2 or 3), the average distance was shorter when observers reported high-level subjective visibility. The findings are compatible with the partial awareness hypothesis, and the visual ensembles and summary statistics hypothesis, which hold that visual awareness is probabilistic. These results also support the visual short-term memory models where many items are stored but with a resolution or noise level that depends on the number of items in memory.

Safety and efficacy of 0.02% and 0.01% atropine on controlling myopia progression: a 2-year clinical trial.

Four hundred myopic children randomly received atropine 0.02% (n = 138) or 0.01% (n = 142) in both eyes once-nightly or only wore single-vision spectacles (control group) (n = 120) for 2 years. Spherical equivalent refractive error (SER), axial length (AL), pupil diameter (PD), and amplitude of accommodation (AMP) were measured every 4 months. After 2 years, the SER changes were - 0.80 (0.52) D, - 0.93 (0.59) D and - 1.33 (0.72) D and the AL changes were 0.62 (0.29) mm, 0.72 (0.31) mm and 0.88 (0.35) mm in the 0.02% and 0.01% atropine groups and control group, respectively. There were significant differences between changes in SER and AL in the three groups (all P < 0.001). The changes in SER and AL in the 2nd year were similar to the changes in the 1st year in the three groups (all P > 0.05). From baseline to 2 years, the overall decrease in AMP and increase in PD were not significantly different in the two atropine groups, whereas the AMP and PD in the control group remained stable (all P > 0.05). 0.02% atropine had a better effect on myopia control than 0.01% atropine, and its effects on PD and AMP were similar to 0.01% atropine. 0.02% or 0.01% atropine controlled myopia progression and AL elongation synchronously and had similar effects on myopia control each year.

The first reported outbreak of an undetermined species of human infection with spotted fever group Rickettsia in Lu'an, China.

OBJECTIVE: On May 2, 2017, an outbreak of unexplained fever with rashes was reported in Lu'an, China. In this study, we aimed to identify the possible pathogens, epidemiological characteristics, and risk factors of this outbreak. METHODS: We conducted descriptive field epidemiological studies. Blood samples were tested using an indirect immunofluorescence assay for Rickettsia rickettsii antibody, and nested polymerase chain reaction and gene sequencing assays were performed. RESULTS: We recruited 39 cases who had symptomatic onset from April 20 to June 8, 2017. Among these, 9 were suspected cases, 18 were probable cases, and 12 were confirmed cases. No one died. The main clinical manifestations were fever (100%), rash (100%), fatigue (97.3%), myalgia (83.8%), and anorexia (83.8%). None of the patients died. Thirty-seven patients who were treated with antibiotics during hospitalization showed significant improvement. The cases were distributed across 14 townships in 2 counties. The median age was 59 (43.0-81.0) years, of which 93.3% had a history of tea picking (28/30), and 77.3% (17/22) had a history of tick bites. The mean incubation period was 5.0 days (2.0-13.0 days). Serum IgG titers were higher in convalescent patients than in the general population (p = 0.016). Phylogenetic analysis revealed that the ompA sequences of Rickettsia sp. Lu'an-2018 had an 86.8%-99.0% sequence identity with the 23 strains of Rickettsia found worldwide. CONCLUSIONS: This was the first reported outbreak of an undetermined species of a human infection with the spotted fever group of Rickettsia in China, which might be caused by ticks biting local residents when picking tea.

Cell-free fetal DNA testing and its correlation with prenatal indications.

BACKGROUND: The prenatal test of cell-free fetal DNA (cffDNA) is also known as noninvasive prenatal testing (NIPT) with high sensitivity and specificity. This study is to evaluate the performance of NIPT and its clinical relevance with various clinical indications. METHODS: A retrospective analysis was conducted on 14,316 pregnant women with prenatal indications, including advanced maternal age (≥35 years), maternal serum screening abnormalities, the thickened nuchal translucency (≥2.5 mm) and other ultrasound abnormalities, twin pregnancy/IVF-ET pregnancy, etc. The whole-genome sequencing (WGS) of maternal plasma cffDNA was employed in this study. RESULTS: A total of 189 (1.32%) positive NIPT cases were identified, and 113/189 (59.79%)cases were confirmed by invasive prenatal testing. Abnormal serological screening (53.14%) was the most common indication, followed by elderly pregnancy (23.02%). The positive prediction value for T21, T18, T13, sex chromosome abnormalities, other autosomal aneuploidy abnormalities, and CNV abnormalities were 91.84, 68.75,37.50, 66.67, 14.29, and 6.45%, respectively. The positive rate and the true positive rate of nuchal translucency (NT) thickening were the highest (4.17 and 3.33%), followed by the voluntary requirement group (3.49 and 1.90%) in the various prenatal screening indications. The cffDNA concentration was linearly correlated with gestational age (≥10 weeks) and the positive NIPT group's Z-score values. CONCLUSIONS: whole-genome sequencing of cffDNA has extremely high sensitivity and specificity for T21, high sensitivity for T18, sex chromosome abnormalities, and T13. It also provides evidence for other abnormal chromosomal karyotypes (CNV and non-21/18/13 autosomal aneuploidy abnormalities). The cffDNA concentration is closely related to the gestational age and determines the specificity of NIPT. Our results highlight NIPT's clinical significance, which is an effective prenatal screening tool for high-quality care of pregnancy.

Continued nucleic acid tests for SARS-CoV-2 following discharge of patients with COVID-19 in Lu'an, China.

BACKGROUND: Studies have shown that discharged Coronavirus disease 2019 (COVID-19) patients have retested positive for SARS-CoV-2 during a follow-up RT-PCR test. We sought to assess the results of continued nucleic acid testing for SARS-CoV-2 patients in COVID-19 patients after they were discharged in Lu'an, China. METHODS: We conducted RT-PCR tests on sputum, throat swabs, fecal or anal swabs, and urine samples collected from 67 COVID-19 patients following discharge. Samples were collected on the 7th and 14th days following discharge. Patients testing positive on the 7th or 14th day were retested after 24 hours until they tested negative twice. RESULTS: Seventeen (17/67, 25.4%) discharged COVID-19 patients had a positive RT-PCR retest for SARS-CoV-2. Among them, 14 (82.4%) were sputum positive, five (29.4%) were throat swab positive, seven (41.2%) were fecal or anal swab positive, one (5.9%) was urine sample positive, five (29.4%) were both sputum and throat swab positive, four (23.5%) were both sputum and fecal test positive, and one (5.9%) was positive of all four specimens. The shortest period of time between discharge and the last positive test was 7 days, the longest was 48 days, and the median was 16 days. The proportion of positive fecal or anal swab tests increased from the third week. The median Cq cut-off values after onset were 26.7 after the first week, 37.7 the second to sixth week, and 40 after the sixth week. There were no significant differences between the RT-PCR retest positive group and the unrecovered positive group. CONCLUSIONS: There was a high proportion of patients who retested positive for COVID-19. Discharge criteria have remained fairly consistent so we encourage regions affected by COVID-19 to appropriately amend their current criteria.