[Clinical analysis of liver chemistries in children and adolescent with 2019-nCoV infection]

Objective: To describe the clinical features of liver involvement in children and adolescent with 2019-nCoV infection. Methods: The clinical data of 77 hospitalized cases admitted to the Children's Hospital of Fudan University were collected from January 19 to November 28, 2020. The characteristics and risk factors of abnormal liver chemistries in children with laboratory-confirmed 2019-nCoV infection were analyzed. Results: Of the 77 cases, 44 were male (57.1%) and 33 were female (42.9%), with a median age of 10 years. 27(35.1%) were asymptomatic, 28(36.4%) had mild illness, 22(28.6%)had non-severe pneumonia. Hydroxychloroquine was used in 7 cases. Of the 75 children without underlying diseases, alanine aminotransferase was elevated in 1 case (1.5%, during hydroxychloroquine therapy), aspartate aminotransferase was elevated in 7 cases (10.3%), alkaline phosphatase was elevated in 7 cases (28%), and total bilirubin, direct bilirubin, albumin, international normalized ratio were in normal range. There was no statistical difference between the pneumonia group and the non-pneumonia group in term of liver chemistries (P > 0.05), same as between the elevated erythrocyte sedimentation rate group and the normal group. There was no aggravation of liver injury in the child with biliary atresia. The child with epilepsy showed no abnormal liver chemistries after infection. Conclusion: Children with 2019-nCoV infection had mild clinical symptoms with few cases of liver injury. The abnormal liver chemistries in children with COVID-19 infection may be related to the underlying disease and the use of antiviral drugs.

Multifunctional microfluidic chip for cancer diagnosis and treatment

Microfluidic chip is not a chip in the traditional sense. It is technologies that control fluids at the micro level. As a burgeoning biochip, microfluidic chips integrate multiple disciplines, including physiology, pathology, cell biology, biophysics, engineering mechanics, mechanical design, materials science, and so on. The application of microfluidic chip has shown tremendous promise in the field of cancer therapy in the past three decades. Various types of cell and tissue cultures, including 2D cell culture, 3D cell culture and tissue organoid culture could be performed on microfluidic chips. Patient-derived cancer cells and tissues can be cultured on microfluidic chips in a visible, controllable, and high-throughput manner, which greatly advances the process of personalized medicine. Moreover, the functionality of microfluidic chip is greatly expanding due to the customizable nature. In this review, we introduce its application in developing cancer preclinical models, detecting cancer biomarkers, screening anti-cancer drugs, exploring tumor heterogeneity and producing nano-drugs. We highlight the functions and recent development of microfluidic chip to provide references for advancing cancer diagnosis and treatment.

Comparison of Three Frailty Scales for Prediction of Adverse Outcomes among Older Adults: A Prospective Cohort Study

OBJECTIVES

To compare the ability of Frailty Phenotype (FP), FRAIL and Frailty Index (FI) to predict adverse outcomes.

DESIGN

A prospective cohort study.

SETTING

A senior community in Beijing, China.

PARTICIPANTS

A total of 188 older adults aged 65 years or older (mean age 84.0 ± 4.4 years, 58.5% female).

MEASUREMENTS

Frailty was evaluated by FP, FRAIL and FI. The agreement between scales was assessed by Cohen kappa coefficient. The predictive value of the three scales for adverse outcomes during one-year follow-up period were analyzed using decision curve analysis(DCA) and receiver operating characteristic curve (ROC) analysis.

RESULTS

Frailty ranged from 25% (FRAIL) to 42.6% (FI). The agreement between scales was moderate to good (Cohen's kappa coefficient 0.44~0.61). DCA showed though the curves of the scales overlapped across all relevant risk thresholds, clinical treating had a higher net benefit than "treat all" and "treat none" when risk of unplanned hospital visits ≥30%, risk of functional decline or falls ≥15%. The three scales had similar predictive value for unplanned hospital visits (area under ROC, AUC 0.63, 0.64 and 0.69). FRAIL and FI had similar predictive value for functional decline (AUC 0.63,0.65). FI had predictive value for falls (AUC 0.65).

CONCLUSIONS

All three scales showed clinical utility but FRAIL may be best in practice because it is simple. Multidimensional measures of frailty are better than unidimensional for prediction of adverse outcomes among older adults.

[Radiomics nomogram of MR: a prediction of cervical lymph node metastasis in laryngeal cancer]

Objective: To establish and validate a radiomics nomogram based on MR for predicting cervical lymph node metastasis in laryngeal cancer. Methods: One hundred and seventeen patients with laryngeal cancer who underwent MR examinations and received open surgery and neck dissection between January 2016 and December 2019 were included in this study. All patients were randomly divided into a training cohort (n=89) and test cohort (n=28) using computer-generated random numbers. Clinical characteristics and MR were collected. Radiological features were extracted from the MR images. Enhanced T1 and T2WI were selected for radiomics analysis, and the volume of interest was manually segmented from the Huiyihuiying radiomics cloud platform. The variance analysis (ANOVA) and the least absolute shrinkage and selection operator (LASSO) algorithm were used to reduce the dimensionality of the radiomics features in the training cohort. Then, a radiomic signature was established. The clinical risk factors were screened by using ANOVA and multivariate logistic regression. A nomogram was generated using clinical risk factors and the radiomic signature. The calibration curve and receiver operator characteristic (ROC) curve were used to confirm the nomogram's performance in the training and test sets. The clinical usefulness of the nomogram was evaluated by decision curve analysis (DCA). Furthermore, a testing cohort was used to validate the model. Results: The radiomics signature consisted of 21 features, and the nomogram model included the radiomics signature and the MR-reported lymph node status. The model showed good calibration and discrimination. The model yielded areas under the ROC curve (AUC) in the training cohort, specificity, and sensitivity of 0.930, 0.930 and 0.875. In the test cohort, the model yielded AUC, specificity and sensitivity of 0.883, 0.889 and 0.800. DCA indicated that the nomogram model was clinically useful. Conclusion: The MR-based radiomics nomogram model may be used to predict cervical lymph node metastasis of laryngeal cancer preoperatively. MR-based radiomics could serve as a potential tool to help clinicians make an optimal clinical decision.

[Regulatory effect of microRNA-126 on macrophage proliferation caused by high glucose stimulation]

Objective: To explore the effects of microRNA-126 (miR-126) on the proliferation of human myeloid leukemia mononuclear cells (THP-1)-derived macrophages in high glucose environment and the regulatory role of miR-126 in periodontitis with diabetes. Methods: THP-1 cells were cultured in vitro and 5 μg/L phorbol-12-myristate-13-acetate was applied to induce THP-1 cells differentiating into macrophages for 48 h in low glucose culture medium (5.5 mmol/L). THP-1-derived macrophages were then cultured with low glucose, medium glucose (15 mmol/L) or high glucose (25 mmol/L) media respectively. The proliferation of THP-1-derived macrophages was detected by cell counting kit-8 (CCK-8) method and the expressions of miR-126 and proliferation-associated factors were detected by quantitative real time PCR (qRT-PCR). The miR-126 mimic or inhibitor was transfected into THP-1-derived macrophages for 72 h. The proliferation of cells was detected by CCK-8 method and the expressions of miR-126 or proliferation-associated factors were detected by qRT-PCR. Results: Increasing glucose concentration decreased the proliferation of THP-1-derived macrophages (day 7, A values in low, medium and high glucose groups were 0.369±0.014, 0.214±0.009 and 0.200±0.010, respectively, P<0.01) as well as the survival rate (P<0.05), promoted the expression of miR-126, B-cell lymphoma-2 (Bcl-2)-associated X protein (BAX) and caspase-3 (P<0.05), and suppressed Bcl-2, phosphoinositol-3 kinase regulatory subunit 2 (PIK3R2) expression (P<0.05). After the miR-126 mimic was transfected in cells in low glucose medium for 72 h, compared with negative control (1.005±0.118), the expression of miR-126 significantly increased (2 980.227±170.431, P<0.05), and the proliferation of THP-1 derived macrophages decreased (negative control: 1.816±0.013, mimic group: 1.310±0.048, P<0.01), the level of BAX and caspase-3 significantly increased (P<0.01, P<0.05), PIK3R2 and Bcl-2 significantly decreased (P<0.05, P<0.01). After the miR-126 inhibitor was transfected in cells cultured in high glucose medium for 72 h, compared with negative control (0.723±0.133), the proliferation of inhibitor group increased (0.984±0.049, P<0.05), the level of BAX and caspase-3 significantly decreased (P<0.01, P<0.05), PIK3R2 and Bcl-2 significantly increased (P<0.01, P<0.05). Conclusions: High glucose condition can inhibit the proliferation of THP-1-derived macrophages and increase the expression of miR-126. MiR-126 can inhibit the proliferation of THP-1-derived macrophages in high glucose environment through up-regulating the expression of BAX and caspase-3 and down-regulating the expression of PIK3R2 and Bcl-2.

[Influence of the stiffness of three-dimensionally bioprinted extracellular matrix analogue on the differentiation of bone mesenchymal stem cells into skin appendage cells]

Objective: To observe the influence of the stiffness of three-dimensionally bioprinted extracellular matrix analogue on the differentiation of bone marrow mesenchymal stem cells (BMSCs) into skin appendage cells. Methods: (1) Sodium alginate of 1 g and 4 g gelatin, 3 g sodium alginate and 8 g gelatin were mixed respectively, and the two mixtures were dissolved in 100 mL ultra-pure water respectively to prepare two sodium alginate-gelatin composite hydrogels, named 1A4G hydrogel and 3A8G hydrogel, which were used in the subsequent experiments. The morphology of the two hydrogels at room temperature, after condensation for 15-30 min at 4 ℃ (the same condensation condition below), after condensation and cross-linking with 25 g/L calcium chloride solution (the same cross-linking condition below), and after condensation and three-dimensional printing with a three-dimensional bioprinter (the same three-dimensional printer below) and cross-linking were observed respectively. Young's modulus (stiffness) of the two kinds of hydrogels was measured by Young's modulus tester after condensation and cross-linking (n=3). Two kinds of hydrogels were cross-linked and freeze-dried, and their pore structure was observed by scanning electron microscope. Two hydrogels were cross-linked and freeze-dried, and the porosity was detected by anhydrous ethanol replacement method (n=3). (2) BMSCs were isolated from femur and tibia of 20 C57BL/6 mice (no limitation with sex, born 7 days) and cultured, and the second passage of cells was used for further test. The BMSCs single cell suspension (1.0×10(7) /mL) was mixed with 1A4G hydrogel and 3A8G hydrogel respectively at 1∶9 volume ratio to prepare BMSCs-loaded 1A4G hydrogel and BMSCs-loaded 3A8G hydrogel for three-dimensional printing. One construct was printed with 1 mL cell-loaded hydrogel (the same dosage for printing below). Mesenchymal stem cells (MSCs) specific medium was added after cross-linking, and the printed constructs were divided into 1A4G group and 3A8G group according to the hydrogel. One construct of each group cultured for 7 days was tested with live/dead kit to count the live cells and dead cells in 50-fold field of view. Nine printed constructs from each of the two groups were taken, and BMSCs of nine wells (1.0×10(6) per well) cultured with 2 mL MSCs specific medium were set as two-dimensional culture group. After 1, 3, 5 day (s) of culture, three printed constructs from 1A4G group and 3A8G group respectively and three wells of cells from two-dimensional culture group were taken to detect the absorbance value in culture medium by cell counting kit 8, denoting the cell proliferation activity. (3) BMSCs-loaded 1A4G hydrogel and BMSCs-loaded 3A8G hydrogel of 10 mL respectively were prepared as in experiment (2), which were respectively mixed with 0.5 mL plantar dermis homogenate extracted from 10 C57BL/6 mice of 1 day postnatal with unknown sex, then three-dimensionally printed, cross-linked, cultured with MSCs specific medium for 3 days and then changed to sweat gland specific medium. The printed constructs were divided into 1A4G group and 3A8G group according to their hydrogel. After 7 days of culture with sweat gland specific medium, the expressions of epithelial cell surface markers cytokeratin-5 (CK5) and CK14, sweat gland cell surface markers CK18 and Na(+) /K(+) -ATPase (NKA), and hair follicle cell surface markers CK17 and alkaline phosphatase (ALP) at protein level in cells of printed constructs in the two groups were detected by immunofluorescence method. The expressions of CK5, CK14, CK18, NKA (detecting ATP1a1), CK17, and ALP at mRNA level in cells of printed constructs in the two groups were detected with real-time fluorescent quantitative reverse transcription polymerase chain reaction (n=3). Data were statistically analyzed with independent sample t test, Fisher's exact probability test, analysis of variance for factorial design, and Bonferroni method. Results: (1) Compared with that of 3A8G hydrogel, 1A4G hydrogel had lower viscosity and better fluidity at room temperature. Both kinds of hydrogels were gel-like after condensation, based on which, the shape of cross-linked hydrogels was uniform and regular, with three-dimensional printing and cross-linking made hrdrogels forming solid crisscross cylindrical constructs. The Young's modulus of 1A4G hydrogel was (52±6) kPa, which was obviously lower than (218±5) kPa of 3A8G hydrogel (t=40.470, P<0.01). The pore structure of the two hydrogels was similar, with all the cross-sections showing porous network structure. The porosity of the two hydrogels was similar (t=0.930, P>0.05). (2) The distribution of live/dead cells between 1A4G group and 3A8G group was similar after 7 days of culture (P>0.05), most of which were live cells. The absorbance value in culture medium of printed constructs among 1A4G group, 3A8G group, and two-dimensional culture group didn't show statistically significant differences after 1, 3, 5 day (s) of culture (P>0.05). Compared with that after 1 day of culture within each group, the absorbance value in culture medium of printed constructs in 1A4G group and 3A8G group was significantly increased after 3 and 5 days of culture (P<0.05 or P<0.01), and the absorbance value in culture medium of cells in two-dimensional culture group was significantly increased after 5 days of culture (P<0.01). Compared with that after 3 days of culture within each group, the absorbance value in culture medium of printed constructs in 1A4G group and 3A8G group and that of cells in two-dimensional culture group was significantly increased after 5 days of culture (P<0.01). (3) After 7 days of culture with sweat gland specific medium, the CK5, CK14, CK18, NKA, CK17, and ALP were positively expressed at protein level in cells of printed constructs in the two groups. After 7 days of culture with sweat gland specific medium, the expressions of CK5, CK14, CK18, and NKA at mRNA level in cells of printed constructs were close between the two groups (t=0.362, 0.807, 0.223, 1.356, P>0.05); the expressions of CK17 and ALP at mRNA level in cells of printed constructs in 3A8G group were 1.96±0.21 and 55.57±11.49, respectively, which were significantly higher than 1.05±0.42 and 2.01±0.27 in 1A4G group (t=3.333, 8.074, P<0.05 or P<0.01). Conclusions: BMSCs cultured three-dimensionally in 1A4G and 3A8G hydrogels tend to differentiate into sweat gland cells, but the BMSCs cultured three-dimensionally in 3A8G hydrogel show a stronger tendency to differentiate into hair follicle cells than the cells cultured in 1A4G hydrogel. It suggests that relatively high stiffness of three-dimensionally bioprinted extracellular matrix analogue facilitates not only differentiation of BMSCs into sweat gland cells, but also their differentiation into hair follicle cells.

MicroRNA-495 attenuates proliferation and inflammatory response in rheumatoid arthritis fibroblast-like synoviocytes through attenuating β-catenin pathway

Fibroblast-like synoviocytes (FLSs) exert a critical effect in the occurrence and progress of rheumatoid arthritis (RA). MicroRNA-495 (miR-495) can regulate many growth behaviors in various cell types. Nevertheless, the role of miR-495 is still unclear in RA-FLS. We aimed to explore the role and molecular mechanism of miR-495 in RA. The FLSs and synovial tissue from normal and RA cases were used in the study. RT-PCR analysis was used to examine the expression of miR-495. Western blot assay was conducted to determine the levels of matrix metalloproteinase-9 (MMP-9), matrix metalloproteinase-2 (MMP-2) and β-catenin. Cell counting kit-8 (CCK-8) assays were performed to determine the proliferation of RA-FLS in different treatment groups. The results showed that miR-495 is down-regulated in both RA-synovial tissue and RA-FLSs. Overexpression of miR-495 could inhibit RA-FLS proliferation and inflammatory factors of interleukin (IL)-6, IL-11 and tumor necrosis factor alpha (TNF-α), and decrease the protein expression of MMP-9 and MMP-2. In addition, miR-495 could negatively regulate the expression of β-catenin in RA-FLSs. We also confirmed that the inhibitory role of miR-495 in RA-FLS is through the regulation of β-catenin expression. Taken together, miR-495 is downregulated in RA-FLS and RA synovial tissue, and miR-495 inhibits proliferation and inflammatory response in RA-FLS, partially via regulating β-catenin expression. The miR-495/β-catenin pathway may serve as a new therapeutic target for RA.

LncRNA-mediated posttranslational modifications and reprogramming of energy metabolism in cancer

Altered metabolism is a hallmark of cancer, and the reprogramming of energy metabolism has historically been considered a general phenomenon of tumors. It is well recognized that long noncoding RNAs (lncRNAs) regulate energy metabolism in cancer. However, lncRNA‐mediated posttranslational modifications and metabolic reprogramming are unclear at present. In this review, we summarized the current understanding of the interactions between the alterations in cancer‐associated energy metabolism and the lncRNA‐mediated posttranslational modifications of metabolic enzymes, transcription factors, and other proteins involved in metabolic pathways. In addition, we discuss the mechanisms through which these interactions contribute to tumor initiation and progression, and the key roles and clinical significance of functional lncRNAs. We believe that an in‐depth understanding of lncRNA‐mediated cancer metabolic reprogramming can help to identify cellular vulnerabilities that can be exploited for cancer diagnosis and therapy.

[Long-term outcome of percutaneous balloon aortic valvuloplasty for children with congenital aortic valve stenosis]

Objective: To assess the efficacy and long-term outcome of percutaneous balloon aortic valvuloplasty (PBAV) for children with congenital aortic stenosis (CAS) and to explore risk factors for significant aortic regurgitation (AR) and reintervention after PBAV during follow up. Methods: This was a retrospective study. Children (≤18 years old) with CAS, who underwent PBAV in Guangdong Provincial Hospital from January 2004 to December 2018, were included in this study. Demographic, preoperative transthoracic echocardiography (TTE) and surgical data were collected. Postoperative complications were closely observed, and the patients were followed up at 1, 6, 12 months after the operation, and then at one year interval thereafter. Endpoint events included significant AR and reintervention. Reintervention was defined as any intervention that needed to be performed on the valve for various reasons, including re-PBAV, surgical valvuloplasty and valve replacement. Significant AR was defined as AR grade≥3 by TTE criteria. The results of the last TTE examination before the end of the study were collected. The Kaplan-Meier curve for long-term AR-free and intervention-free survival was plotted. Cox regression model was used to further analyze the risk factors for significant AR and reintervention after PBAV in CAS patients. Results: A total of 55 patients were enrolled in this study, and the age was 4.6(1.6, 6.5) years, with 37(67.3%) males. The peak systolic valve gradient fell from (80.3±30.6)mmHg to (38.5±18.5)mmHg(P<0.001, 1 mmHg=0.133 kPa). Surgical success rate was 89% (49/55). Acute post-PBAV AR occurred in 18 patients, including 3 patients with RA≥3 grade. In-hospital complications occurred in 6 patients (2 deaths, 2 cases of transient arrhythmia, and 2 cases of femoral artery embolization). Fifty patients accomplished the follow-up and the follow-up time was 6.2(3.4, 8.5) years. Significant AR was found in 20 patients. Significant AR-free survival rate was 53% at 5 years and 19% at 10 years. Reintervention was performed in 11 patients (4 with valvuloplasty and 7 with valve replacement), and the 5-year and 10-year intervention-free survival rates were 87% and 62%, respectively. Multivariate Cox regression analysis showed that acute post-PBAV AR was a risk factor for long-term significant AR (HR=2.398, 95%CI 1.007-5.712, P=0.048). Post-PBAV residual pressure gradient ≥ 35 mmHg (HR=4.747, 95%CI 1.116-19.329, P=0.030)and acute post-PBAV AR (HR=5.104, 95%CI 1.083-24.065, P=0.039)were risk factors for re-intervention. Conclusions: PBAV is safe and effective in the treatment of CAS in children, but attention should be paid on significant AR post procedure. Acute post-PBAV AR is a risk factor for re-intervention and significant AR post PBAV, and high post-PBAV residual pressure gradient is a risk factor for re-intervention.

[Analysis of Correlation between Gene Polymorphisms of CRHBP in Yunnan Han Population and Schizophrenia and Aggressive Behavior]

Objective To explore the correlation between 4 tag single nucleotide polymorphisms （Tag SNP） sites （rs7721799, rs32897, rs7718461, rs10062367） of corticotropin releasing hormone binding protein （CRHBP） and schizophrenia and aggressive behavior in the Yunnan Han population. Methods Case-control correlation analysis was used to establish a complex amplification system. Improved multiplex ligase detection reaction （iMLDR） technology was used to detect the genotypes of 4 SNP sites of CRHBP gene of 163 Han schizophrenic patients （including 81 patients with aggressive behavior, 82 patients without aggressive behavior） and 345 healthy Han individuals, which were analyzed statistically by SPSS 19.0, Haploview 4.2 and PHASE 2.1 software. Results There was no correlation between the 3 SNP sites of CRHBP gene and the onset of schizophrenia except for the rs7718461 site （P>0.05）. The relative risk of aggressive behavior of patients carrying GG or GA genotype at rs7718461 site were 4.903 times higher than those carrying AA genotype （P<0.05）. Conclusion The CRHBP gene may not be associated with the occurrence of schizophrenia in Yunnan Han population, but AA genotype of rs7718461 may reduce the risk of aggressive behavior in schizophrenia patients.

[Therapeutic efficacy analysis of immunotherapy in small cell lung cancer]

Objective: Recently, increasing number of lung cancer patients benefit from immune-checkpoint inhibitors (ICIs). However, the data of Chinese small cell lung cancer (SCLC) patients is limited. This study aims to analyze the response and survival data of ICIs treatment in SCLC and to explore the predictive biomarkers. Methods: Forty-seven SCLC patients who received ICIs treatment from Peking University Cancer Hospital from May 2017 to September 2019 was recruited. Clinical characteristics including sex, age, smoking status, ICIs strategy, PD-L1 expression and therapeutic efficacy were collected to explore the clinical predictive biomarkers for SCLC ICIs treatment. Results: Among the 47 patients, 18 (38.3%) cases were partial repose (PR), 11 (23.4%) were stable disease (SD), 18 (38.3%) were progressive disease (PD), and the objective response rate (ORR) was 38.3%, disease control rate (DCR) was 61.7%, the median progression-free survival (PFS) was 5.3 months. ICIs monotherapy accounts for 27.7%, the ORR was 15.4%, DCR was 53.8%, median PFS was 2.7 months. Combined therapy accounts for 72.3%, the ORR was 47.1%, DCR was 64.7%, median PFS was 5.4 months. Fourteen (29.8%) patients received ICIs as the first line treatment, their ORR was 85.7%, DCR was 100%, median PFS was 9.1 month. The ORR was not related to the age, sex, body mass index (BMI), smoking status and programmed death-ligand 1 (PD-L1) expression (P>0.05). The ORRs were higher in patients underwent PD-L1 monotherapy (P=0.001), combined therapy (P=0.002) and received ICIs as the first line treatment (P<0.001). Log-rank analysis indicated that the PFS of female patients were 12.0 months, significantly longer than 4.4 months of male patients in ICIs treatment (P=0.038). Patients who received PD-L1 monotherapy, combined treatment, or ICIs as the first line treatment had longer PFS than their counterparts, though no statistical significant was observed (P>0.05). Cox multivariate analysis showed that, the gender was not an independent predictor for PFS in ICIs treatment (HR=3.777, 95%CI=0.974~30.891, P=0.054). Conclusions: Immunotherapy is an effective treatment strategy for SCLC. Patients who receive combined ICIs treatment, first line ICIs treatment and PD-L1 treatment may get greater benefits. PD-L1 expression cannot predict the response and PFS in SCLC ICIs treatment.

The Biological Functions and Clinical Applications of Integrins in Cancers

Integrins are the adhesion molecules and receptors of extracellular matrix (ECM). They mediate the interactions between cells-cells and cells-ECM. The crosstalk between cancer cells and their microenvironment triggers a variety of critical signaling cues and promotes the malignant phenotype of cancer. As a type of transmembrane protein, integrin-mediated cell adhesion is essential in regulating various biological functions of cancer cells. Recent evidence has shown that integrins present on tumor cells or tumor-associated stromal cells are involved in ECM remodeling, and as mechanotransducers sensing changes in the biophysical properties of the ECM, which contribute to cancer metastasis, stemness and drug resistance. In this review, we outline the mechanism of integrin-mediated effects on biological changes of cancers and highlight the current status of clinical treatments by targeting integrins.

[The role of large-scale testing platform in the prevention and control of the COVID-19 pandemic: an empirical study based on a novel numerical model]

Objective: China adopted an unprecedented province-scale quarantine since January 23rd 2020, after the novel coronavirus (COVID-19) broke out in Wuhan in December 2019. Responding to the challenge of limited testing capacity, large-scale (>20 000 tests per day) standardized and fully-automated laboratory (Huo-Yan) was built as an ad-hoc measure. There is so far no empirical data or mathematical model to reveal the impact of the testing capacity improvement since quarantine. Methods: Based on the suspected case data released by the Health Commission of Hubei Province and the daily testing data of Huo-Yan Laboratory, the impact of detection capabilities on the realization of "clearing" and "clearing the day" of supected cases was simulated by establishing a novel non-linear and competitive compartments differential model. Results: Without the establishment of Huo-Yan, the suspected cases would increase by 47% to 33 700, the corresponding cost of quarantine would be doubled, the turning point of the increment of suspected cases and the achievement of "daily settlement" (all newly discovered suspected cases are diagnosed according to the nucleic acid testing result) would be delayed for a whole week and 11 days. If the Huo-Yan Laboratory could ran at its full capacity, the number of suspected cases could start to decrease at least a week earlier, the peak of suspected cases would be reduced by at least 44%, and the quarantine cost could be reduced by more than 72%. Ideally, if a daily testing capacity of 10 500 tests was achieved immediately after the Hubei lockdown, "daily settlement" for all suspected cases could be achieved. Conclusions: Large-scale, standardized clinical testing platform, with nucleic acid testing, high-throughput sequencing, and immunoprotein assessment capabilities, need to be implemented simultaneously in order to maximize the effect of quarantine and minimize the duration and cost of the quarantine. Such infrastructure, for both common times and emergencies, is of great significance for the early prevention and control of infectious diseases.

Improved Constraints on Sterile Neutrino Mixing from Disappearance Searches in the MINOS, MINOS+, Daya Bay, and Bugey-3 Experiments

Searches for electron antineutrino, muon neutrino, and muon antineutrino disappearance driven by sterile neutrino mixing have been carried out by the Daya Bay and MINOS+ collaborations. This Letter presents the combined results of these searches, along with exclusion results from the Bugey-3 reactor experiment, framed in a minimally extended four-neutrino scenario. Significantly improved constraints on the θ_{μe} mixing angle are derived that constitute the most constraining limits to date over five orders of magnitude in the mass-squared splitting Δm_{41}^{2}, excluding the 90% C.L. sterile-neutrino parameter space allowed by the LSND and MiniBooNE observations at 90% CL_{s} for Δm_{41}^{2}<13  eV^{2}. Furthermore, the LSND and MiniBooNE 99% C.L. allowed regions are excluded at 99% CL_{s} for Δm_{41}^{2}<1.6 eV^{2}.

[Application of intestinal stent in prevention of anastomotic leakage after rectal cancer operation]

Objective: To observe preventive effect of intestinal stent against anastomotic leakage after rectal cancer operation. Methods: A retrospective cohort study was carried out. Clinical data of 107 patients with low rectal cancer undergoing laparoscopic radical resection from January 2015 to August 2019 were retrospectively analyzed. Intestinal stent was placed intraoperatively in 48 cases and was not placed in 59 cases. Postoperative Wexner score for anal function and incidence of anastomotic leakage were compared between patients with and without intstinal stent. Results: There was no significant differences in age, distance between tumor and the anal verge, operative time and postoperative Wexner score for anal function between the two groups (all P>0.05). After a month of follow-up, the incidence of anastomotic leakage was 16.9% (10/59) in the non-stent group, while no anastomotic leakage was found in the stent group (P=0.002). Conclusion: Placement of intestinal stent can effectively prevent anastomotic leakage after low rectal cancer surgery.

[Effects of SGI-1027 on Formation and Elimination of PrP^(Sc) in Prion-Infected Cells]

Recently, SGI-1027, a well-known inhibitor of DNA-methyl transferases (DNMTs), was reported to effectively reduce formation of pathogenic PrP^(Sc) in prion-infected cells. Herein, we confirm the elimination of PrP^(Sc) in chronic wasting disease (CWD) prion-infected neurons by SGI-1027, and pinpoint the binding region of human prion protein to SGI-1027. SGI-1027 is broadly functional against various prion disease types, including human prions. Previously, the inhibitory effects of SGI-1027 on DNMT function is well tested in various cell culture models. While neither treatment with a DNMTs enhancer S-adenosyl-L-methionine (SAM), nor with their inhibitor, 5-azacytidine, prevented PrP^(Sc) propagation, SGI-1027 did. Our study suggest that the anti-prion effects of SGI-1027 are a result of its direct interaction with PrP^(C), which effectively interferes with the pathogenic conformational change of PrP^(C) to PrP^(Sc). We conclude that SGI-1027 driven suppression of pathogenic PrP^(Sc) is independent of DNMT.

Positive-Parity Linear-Chain Molecular Band in ^{16}C

An inelastic excitation and cluster-decay experiment ^{2}H(^{16}C,^{4}He+^{12}Be or ^{6}He+^{10}Be)^{2}H was carried out to investigate the linear-chain clustering structure in neutron-rich ^{16}C. For the first time, decay paths from the ^{16}C resonances to various states of the final nuclei were determined, thanks to the well-resolved Q-value spectra obtained from the threefold coincident measurement. The close-threshold resonance at 16.5 MeV is assigned as the J^{π}=0^{+} band head of the predicted positive-parity linear-chain molecular band with (3/2_{π}^{-})^{2}(1/2_{σ}^{-})^{2} configuration, according to the associated angular correlation and decay analysis. Other members of this band were found at 17.3, 19.4, and 21.6 MeV based on their selective decay properties, being consistent with the theoretical predictions. Another intriguing high-lying state was observed at 27.2 MeV which decays almost exclusively to ^{6}He+^{10}Be(∼6  MeV) final channel, corresponding well to another predicted linear-chain structure with the pure σ-bond configuration.

PD-1/PD-L1 Based Combinational Cancer Therapy: Icing on the Cake

Cancer has been a major global health problem due to its high morbidity and mortality. While many chemotherapy agents have been studied and applied in clinical trials or in clinic, their application is limited due to its toxic side effects and poor tolerability. Monoclonal antibodies specific to the PD-1 and PD-L1 immune checkpoints have been approved for the treatment of various tumors. However, the application of PD-1/PD-L1 inhibitors remains suboptimal and thus another strategy comes in to our sight involving the combination of checkpoint inhibitors with other agents, enhancing the therapeutic efficacy. Various novel promising approaches are now in clinical trials, just as icing on the cake. This review summarizes relevant investigations on combinatorial therapeutics based on PD-1/PD-L1 inhibition.

[Clinical analysis of 27 cases with descending necrotizing mediastinitis]

Objective: To explore the clinical manifestation and treatment strategy for descending necrotizing mediastinitis (DNM). Methods: A total of 27 cases diagnosed as DNM from January 2010 to August 2018 in the First People's Hospital of Foshan were reviewed. There were 16 males and 11 females, age ranged from 16 to 84 years. The clinical data were collected. SPSS 16.0 software and chi square test were used for statistical analysis. Results: ALL 27 cases were diagnosed as DNM by contrast-enhanced CT scan of the neck and chest. Among the 27 cases, 13 cases resulted from peritonsillar abscess, 8 cases from esophageal foreign body perforation, 5 cases from parapharyngeal and retropharyngeal space abscess, and one case from infection of oral cavity. These 27 cases were divided into three subtypes according to the sites of mediastinitis, including 11 cases for typeⅠ, 5 cases for type ⅡA and 11 cases for type ⅡB. Of 27 cases, 20 cases underwent transcervical drainage for DNM, of which 5 cases with tracheotomy and 6 cases with thoracic drainage, and finally 19 of the 20 patients were cured, and one patient died of bacteremia; 7 cases refused to received surgery and were routinely treated with antibiotics, of which, one case was cured and 6 cases died. The curative rate in patients underwent surgery was significantly higher than that in patients treated with medication (χ(2)=13.638, P<0.001). Among the 20 cured cases, 4 cases were combined with diabetes mellitus and 6 cases with necrotizing fasciitis, while in the 7 died cases, 5 cases were combined with diabetes mellitus and 6 cases with necrotizing fasciitis. The comorbidity rates of diabetes mellitus (χ(2)=4.074, P=0.044) and necrotizing fasciitis (χ(2)=4.457, P=0.035) in died cases were significantly higher than those in cured cases. Conclusion: DNM is a serious infection, with high mortality especially in patients with diabetes and necrotizing fasciitis. Timely cervical and chest enhanced CT scan play vital role in its diagnosis. DNM can be treated effectively with transcervical drainage.

Chiral fermion reversal in chiral crystals

In materials chiral fermions such as Weyl fermions are characterized by nonzero chiral charges, which are singular points of Berry curvature in momentum space. Recently, new types of chiral fermions beyond Weyl fermions have been discovered in structurally chiral crystals CoSi, RhSi and PtAl. Here, we have synthesized RhSn single crystals, which have opposite structural chirality to the CoSi crystals we previously studied. Using angle-resolved photoemission spectroscopy, we show that the bulk electronic structures of RhSn are consistent with the band calculations and observe evident surface Fermi arcs and helical surface bands, confirming the existence of chiral fermions in RhSn. It is noteworthy that the helical surface bands of the RhSn and CoSi crystals have opposite handedness, meaning that the chiral fermions are reversed in the crystals of opposite structural chirality. Our discovery establishes a direct connection between chiral fermions in momentum space and chiral lattices in real space.