Coronavirus disease 2019 (COVID-19) has continued to spread globally since late 2019, representing a formidable challenge to the world's healthcare systems, wreaking havoc, and spreading rapidly through human contact. With fever, fatigue, and a persistent dry cough being the hallmark symptoms, this disease threatened to destabilize the delicate balance of our global community. Rapid and accurate diagnosis of COVID-19 is a prerequisite for understanding the number of confirmed cases in the world or a region, and an important factor in epidemic assessment and the development of control measures. It also plays a crucial role in ensuring that patients receive the appropriate medical treatment, leading to optimal patient care. Reverse transcription-polymerase chain reaction (RT-PCR) technology is currently the most mature method for detecting viral nucleic acids, but it has many drawbacks. Meanwhile, a variety of COVID-19 detection methods, including molecular biological diagnostic, immunodiagnostic, imaging, and artificial intelligence methods have been developed and applied in clinical practice to meet diverse scenarios and needs. These methods can help clinicians diagnose and treat COVID-19 patients. This review describes the variety of such methods used in China, providing an important reference in the field of the clinical diagnosis of COVID-19.
Humans ; Artificial Intelligence ; China ; COVID-19/diagnosis* ; COVID-19 Testing

In order to solve the problem that the early onset of paroxysmal atrial fibrillation is very short and difficult to detect, a detection algorithm based on sparse coding of Riemannian manifolds is proposed. The proposed method takes into account that the nonlinear manifold geometry is closer to the real feature space structure, and the computational covariance matrix is used to characterize the heart rate variability (RR interval variation), so that the data is in the Riemannian manifold space. Sparse coding is applied to the manifold, and each covariance matrix is represented as a sparse linear combination of Riemann dictionary atoms. The sparse reconstruction loss is defined by the affine invariant Riemannian metric, and the Riemann dictionary is learned by iterative method. Compared with the existing methods, this method used shorter heart rate variability signal, the calculation was simple and had no dependence on the parameters, and the better prediction accuracy was obtained. The final classification on MIT-BIH AF database resulted in a sensitivity of 99.34%, a specificity of 95.41% and an accuracy of 97.45%. At the same time, a specificity of 95.18% was realized in MIT-BIH NSR database. The high precision paroxysmal atrial fibrillation detection algorithm proposed in this paper has a potential application prospect in the long-term monitoring of wearable devices.
Algorithms ; Atrial Fibrillation ; Databases, Factual ; Electrocardiography ; Humans ; Wearable Electronic Devices

Objective:To investigate the effects of TNF-α knockout on liver and spleen neutrophil responses to Vibrio vulnificus bloodstream infection in a mouse model. Methods:(1) TNF-α-knockout (TNF-α -/-) and wild-type (WT) C57BL/6J mice aged 6-8 weeks were randomly divided into four groups with six in each group: uninfected WT group, infected WT group, uninfected TNF-α -/- group and infected TNF-α -/- group. The mouse model of bloodstream infection was constructed by intraperitoneal injection of Vibrio vulnificus CGMCC1.1758 (2×10 8 CFU/200 μl), while the mice in the uninfected groups were injected intraperitoneally with equal amount of PBS. (2) Liver immune cells and splenocytes were isolated 4 h after infection and subjected to analyze the percentages and numbers of neutrophils, and the changes in cell viability, cellular reactive oxygen species (ROS) level and phagocytosis by flow cytometry. In addition, effects of Vibrio vulnificus bloodstream infection on mTOR signaling pathway in murine neutrophils were evaluated in vivo. Results:(1)Compared with the uninfected WT group, the percentages and numbers of neutrophils in liver and spleen tissues of the infected WT group increased significantly. The percentage and number of liver neutrophils were significantly higher in the infected TNF-α -/- group than in the infected WT group, but no significant difference in spleen neutrophils was detected between the two groups. (2) Compared with the infected WT group, the phagocytosis of liver neutrophils rather than that of spleen neutrophils was enhanced in the infected TNF-α -/- group. (3) The survival rates of neutrophils in both liver and spleen were decreased, while the cellular ROS level was significantly increased in the infected WT group compared with those of the uninfected WT group. Compared with the infected WT group, the infected TNF-α -/- group had increased survival rates of both liver and spleen neutrophils, but decreased level of ROS. (4) The levels of p-AKT (S473) in liver and spleen neutrophils of the infected WT group were lower than those of the uninfected WT group. Compared with the infected WT group, the infected TNF-α -/- group had lower level of p-AKT (S473) in liver neutrophils, but higher p-AKT (S473) level in spleen neutrophils. There were no significant differences in p-4E-BP1(T37/46) levels between the uninfected WT group and the infected WT group. The p-4E-BP1 (T37/46) level in liver neutrophils was lower in the infected TNF-α -/- group than in the infected WT group, but no significant difference in p-4E-BP1 (T37/46) levels in spleen neutrophils was observed between the two groups. Conclusions:TNF-α had different effects on the neutrophils in spleen and liver tissues of mice with Vibrio vulnificus bloodstream infection. It played a critical role in regulating the recruitment, phagocytic function and mTOR signaling of liver neutrophils after Vibrio vulnificus infection in vivo.

Objective To study the treatment outcomes using transcatheter arterial chemoemboliza tion (TACE) followed by hepatic resection (HR) in patients with BCLC stage B hepatocellular carcinoma (HCC).Methods The clinical data of 46 patients with intermediate stage HCC in the Third Affiliated Hospital of Sun Yat-sen University from Jan.2004 to Jul.2013 were analyzed retrospectively.The baseline characteristics of these 46 patients were recorded.The levels of serum aspartate transaminase (AST),ala nine aminotransferase (ALT),total bilirubin (TBil),and albumin (Alb),and the prothrombin time (PT) at 1 week and 1 month after HR were compared with those at the baseline.The overall survival (OS) and progression-free survival (PFS) were analyzed by the Kaplan-Meier method.The effect on PFS by the changes in the alpha-fetal protein level and the modified Response Evaluation Criteria In Solid Tumors (mRECIST) after TACE were analyzed using the log-rank test.Results The number of cycles of TACE given before HR was 1.7 ± 1.1.The mean time interval between TACE and HR was 3.0 ± 3.2 months.The levels of serum AST,ALT,TBil,Alb and PT at 1 week after HR were significantly different from the baseline levels (P ＜ 0.05),while those levels at 1 months after HR showed no significant difference from the baseline levels (P＞0.05).The mean OS was 72.1 ±6.0 (95％ CI 60.36 ～83.86) months.The median PFS was 46.0 (95％ CI:42.60～49.40) months.Using the log-rank test,the decrease in AFP (P ＜ 0.001) and the improvement in mRECIST (CR + PR) (P ＜ 0.001) after TACE were significantly associated with better PFS.Conclusions HR after TACE was safe for patients with BCLC stage B HCC and might prolong the PFS and OS.Decreases in AFP level and improvement in mRECIST (CR + PR) after TACE were factors they could be used to predict the survival outcomes of HR.

Objective To observe the effect of Delta-like ligand 4 (Dll-4) on the pathological structure of retina in early diabetic rats (DM) and its relationship with vascular endothelial growth receptor-2 (VEGFR-2).Methods A total of 70 male Sprague-Dawley rats were randomly divided into normal group and DM group,with 10 and 60 rats in each group,respectively.The rats of DM group was induced by intraperitoneal injection of streptozotocin to established DM model.The rats with blood glucose recovery and death were excluded,and the final 60 rats were included in the statistics.Rats in the normal group were injected with an equal volume of citric acid-sodium citrate buffer.Rats in the DM group were divided into DM 1 month (DM lm) group,DM 2 months (DM 2m) group,DM 3 months (DM 3m) group and DM 3m + Anti group,DM 3m + phosphate buffer solution (PBS) group by random number table method,and 10 rats in each group.In the DM 3m+Anti group,4 μl ofantiDll-4 polyclonal antibody was injected into the vitreous cavity,and the antibody concentration was 0.25 mg/ml.The DM 3m+PBS group was intravitreally injected with an equal volume of PBS.Five days after the injection,the rats were sacrificed.Rats in the DM 3m group and the normal group were not treated,and were sacrificed 3 months after the model was established.The structure and microvascular changes of the retina were observed by hematoxylin-eosin staining,and the total thickness of the retina was measured.The expression of Dll-4 and VEGFR-2 in the retina was detected by immunohistochemistry and fluorescence quantitative polymerase chain reaction (PCR).One-way analysis of variance was used to compare the expression of Dll-4 and VEGFR-2 in the retina of each group.The least significant difference t test was used to compare the two groups.Results Light microscopy showed that the retinal ganglion cells layer in the DM 3m group were obviously edematous,the inner and outer nuclear layers were thinner,the number of cells was reduced,the arrangement was disordered,the edema of outer plexiform layer was obvious,and the microvessels were abnormally dilated.In the DM 3m+Anti group,the edema of outer plexiform layer was lessened than that of the DM 3m group,and the other layers were not significantly different from the DM 3m group.Compared with the normal group,the total retinal thickness of the DM 3m group,the DM 3m+Anti group and the DM 3m+PBS group increased (t=5.596,3.290,4.286;P=0.000,0.008,0.002).Immunohistochemical staining showed that a small amount of Dl14 was positively expressed in the retinal ganglion cell layer of the normal group;a small amount of VEGFR-2 was positively expressed in the ganglion cell layer and the inner and outer nuclear layers.The positive expression of Dll-4 and VEGFR-2 in retinal vascular endothelial cells of DM 3m group increased significantly.The expression of Dll-4 was significantly decreased in the retinal layers and vascular endothelial cells ofDM 3m+Anti group,while the expression of VEGFR-2 was significantly increased.There was no significant difference between the positive expression of Dll4 and VEGFR-2 in the DM 3m+PBS group and the DM 3m group.The results of real-time PCR showed that the relative expression of Dll-4 and VEGFR-2 mRNA in the DM 3m group was significantly higher than that in the normal group (t=6.705,20.871;P＜0.05).Compared with DM 3m group,the relative expression of Dll-4 mRNA in DM 3m+Anti group decreased,and the relative expression of VEGFR-2 mRNA increased (t=2.681,3.639;P＜0.05).The relative expressions of Dll-4 and VEGFR-2 mRNA in the DM 3m+PBS group and DM 3m group were not statistically significant (t=0.513,0.657;P＜0.05).Conclusions The expression of Dll-4 in retinal vascular endothelial cells is gradually increased during the early retinopathy of DM rats.The expression of Dll-4 is inhibited,the expression of VEGFR-2 is up-regulated,and the plexus edema is alleviated.

Objective: To evaluate the medium and long term outcomes of tension-free mid-urethral sling in the treatment of female patients with mixed urinary incontinence (MUI).Methods: Twenty-six patients who underwent the tension-free mid-urethral sling procedure for MUI from April, 2010 to September, 2016, were followed up.Four of the 26 patients underwent retropubic tension free mid-urethral sling (TVT), and 22 of them underwent transurethral middle obturator sling (TOT).Scales were used in the follow-up, such as urinary incontinence severity score (UISS), detrusor instability score (DIS), incontinence quality of life scale evaluation (I-QOL), Urogenital Distress Inventory short form (UDI-6), and the outcomes before and after the procedure were compared.Results: The mean age was 62 years, with a range of 42-80 years.The mean body mass index (BMI) was 26.82 kg/m2, with a range of 21.48-31.14 kg/m2.The mean follow-up time was 26 months, with a range of 8-69 months.Twelve patients never took M-blockers and the rest 14 patients took M-blockers within two weeks.None of the pa-tients had complications, including dysuria, injury of bladder, urethra, obturator vessel or nerve during the surgery.After pulling out the catheter, no one suffered moderate or severe pain or difficulty of urination.The overall cure rate for stress urinary incontinence (SUI) was 96.15% with 25 patients cured, and for urge urinary incontinence (UUI) was 76.92% with 20 patients cured.The patients'' life quality also improved significantly (P<0.05).Conclusion: Ten of the 26 patients showed an overactive bladder according to urodynamic study, from whom all of the six failed patient were.And 16 patients didn''t show an overactive bladder, which may due to two reasons.One is that their sense of urge is not so serious, the other one is that their sense of urge is from urethra.Proximal urethra is full of nerve, which plays a role in sense and urine control.The sense of urge may come from urethra instead of bladder.Tension-free mid-urethral sling procedure is an effective treatment for women with mixed urinary incontinence.Even without taking the M-blockers, the cure rate for urge incontinence reached 76.92%.The efficacy of surgery remained stable in medium and long term, and the patients'' quality of life improved significantly.

Objective To evaluate the predictive value of neutrophil-to-lymphocyte ratio (NLR) and hemoglobinto-white blood cell ratio (HWR) prior to treatment in prognosis of non-operative esophageal squamous cell carcinoma (ESCC) patients.Methods From October 2009 to November 2014,a total of 362 non-operative ESCC patients were enrolled in this prospective study.x2 test was used to analyze the relationship between NLR,HWR and general clinical features;Univariate and multivariate Cox regression analysis was performed to evaluate the association between variables and prognosis of non-operative ESCC patients.Results The optimal cutoff level of 1.23 for NLR and 24.92 for HWR were identified by X-title software.x2 test indicated NLR was significantly associated with gender,tumor length,T stage,TNM stage and fasting blood glucose level.Moreover,univariate and multivariate analyses showed that high NLR and high HWR were all associated with a poor prognosis in non-operative ESCC.However,when patients were specifically stratified by treatment modus,subset analysis showed that NLR was only predictive of prognosis in the concurrent chemoradiotherapy group (HR =4.080,95％ CI:1.074-15.497,P =0.039),whereas the influence of HWR on prognosis was just existed in the sequential chemoradiotherapy group (HR =2.625,95％ CI:1.311-5.254,P =0.006).Conclusions In this investigation,we found that high NLR and high HWR were associated with poor prognosis in non-operative ESCC.

Objective:To discuss the causes and effective measures of prevention and treatment of chylous fistula after central lymph node dissection (CLND) of thyroid cancer. Methods:A total of 6 127 patients who underwent CLND of thyroid cancer in the Tianjin Medical University Cancer Institute and Hospital between July 2013 and June 2015 were analyzed;of which, 14 patients acquired the complication of postoperative chylous fistula. The following conservative treatments were initially performed:systemic therapy, local pressure bandaging, normal pressure drainage, 50%glucose injection, or pingyangmycin injection through a drainage tube. Surgical op-eration was then conducted when the efficacy of the treatment was poor. Results:After the conservative treatment of the 14 patients, the drainage volume gradually decreased in 12 patients, and surgery was performed on the remaining two patients. Conclusion:The CLND of thyroid cancer must be carefully conducted to prevent postoperative chylous fistula. An active conservative treatment must be the first option when chylous fistula occurs. Surgery must only be performed if the treatment is invalid.

OBJECTIVE To explore the expression of Maspin in invasive fungal rhinosinusitis (IFRS) and the value of Maspin in the diagnosis of IFRS. METHODS Forty two cases of fungal rhinosinusitis (FRS) were set as the experimental group, which included 12 cases of IFRS and 30 cases of noninvasive fungal rhino-sinusitis (NIFRS). At the same time, 30 cases of chronic rhino-sinusitis were set as control group. Immunohistochemistry (IHC) was used to detect the expression of Maspin. RESULTS Compared with the control group, the expression of Maspin in FRS group decreased statistically (t=-3.367, P<0.05). The IFRS group, compared with other two groups, had the lowest expression of Maspin (t=-3.390, P<0.05; t=-4.143, P<0.05). By using Maspin score of 5.70 as the cut-off point, the sensitivity and specificity for the diagnosis of IFRS was 91.7% and 88.3% respectively. CONCLUSION The expression of Maspin is very low in IFRS group. Down-regulation of Maspin expression may be a potential indicator for diagnosis of IFRS.