[Quantitative evaluation of early stage blood flow change status after radiofrequency ablation based on multi-slice spiral CT whole-liver perfusion imaging on small hepatocellular carcinoma].

Objective: To investigate the blood flow change status in early stage tumor-related areas of hepatocellular carcinoma and its clinical significance after radiofrequency ablation using multi-slice spiral CT whole-liver perfusion imaging technology. Methods: 21 cases of primary liver cancer that underwent CT-guided radiofrequency ablation were included. CT perfusion scans were divided into four groups according to the time points of CT scans (before surgery, immediately after surgery and 1 and 3 month after surgery), and then blood perfusion parameters of the corresponding areas of the tumor were measured. Statistical analysis was performed using two independent samples of non-parametric Wilcoxon rank-sum test. The differences of blood perfusion parameters between tumor or ablation lesion and background liver parenchyma, paratumor tissue or inflammatory response zone were compared before, immediately and 1 and 3 months after surgery, respectively. Results: (1) The hepatic arterial perfusion (HAP) and hepatic arterial perfusion index (HPI) of cancerous liver tumors and background liver parenchyma was significantly increased (P < 0.01). The total liver perfusion (TLP) was higher than the background liver parenchyma (P = 0.01 < 0.05). The time to peak (TTP) was significantly lower than background liver parenchyma (P < 0.01); (2) The perfusion parameters of HAP, PVP and TLP were lower than the background liver parenchyma in the complete ablation lesions immediately after radiofrequency ablation and 1 and 3 months after surgery, and the difference was statistically significant (P < 0.05); (3) The inflammatory response zone of ablation lesions of HAP, HPI, and TLP were gradually decreased with the extended postoperative time and TTP was gradually increased, while PVP did not change significantly; (4) HAP, HPI, and TTP were compared between the tumor and the tumor inflammatory response zone immediately after surgery, and 1 and 3 months after surgery, and the difference was statistically significant (P < 0.01). However, there was no statistically significant difference between PVP and TLP (P > 0.05). Conclusion: CT whole-liver perfusion imaging can precisely evaluate the early stage blood flow change status in peritumor and tumors before and after radiofrequency ablation and then objectively evaluate tumor's blood supply and therapeutic effect on hepatocellular carcinoma.

[Using the big data of internet to understand the characteristics of coronavirus disease 2019: a big data study].

Objective: To analyze the symptom characteristics of Coronavirus Disease 2019(COVID-19) and to improve its prevention by using big data. Methods: Using Baidu Index Platform (http://index.baidu.com) and the website of Chinese Center for Disease Control and Prevention as data resources, we obtained the search volume (SV) of keywords for symptoms associated with COVID-19 from January 1 to February 20 in each year from 2017 to 2020, in Hubei province and other top 10 impacted provinces in China and the epidemic data. Data of 2020 were compared with the previous three years. Data of Hubei province were compared with confirmed cases. The differences and characteristics of the SV of COVID-19-related symptoms, and the correlation between the SV of COVID-19 and new confirmed or suspected cases were analyzed and the hysteresis effects were discussed. R3.6.2 software was used to analyze the data. Results: Compared the data from January 1 to February 20, 2020, with the SV for the same period of previous three years, Hubei's SV for cough, fever, diarrhea, chest tightness, dyspnea and other symptoms were significantly increased. The total SV of lower respiratory symptoms was significantly higher than that of upper respiratory symptoms (P<0.001). The SV of COVID-19 in Hubei province was significantly correlated with new confirmed or suspected cases (r(confirmed)=0.723, r(suspected)=0.863, all P<0.001). The results of the distributed lag model suggested that the patients who retrieved relevant symptoms on the internet may begin to see a doctor in 2-3 days later and be diagnosed in 3-4 days later. Conclusions: The total SV of lower respiratory symptoms is higher than that of upper respiratory symptoms, and the SV of diarrhea also increases significantly. It warns us to pay attention to not only the symptoms of lower respiratory tract, but also the gastrointestinal symptoms, especially diarrhea in patients with COVID-19. There is a relationship between internet retrieval behavior and the number of new confirmed or suspected cases. Big data have a certain role in the early warning of infectious diseases.

An improved RT-IPCR for detection of pyrene and related polycyclic aromatic hydrocarbons.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous homogeneous chemicals which are well known by carcinogens, mutagens and endocrine disorder. Here, an improved real-time immuno-PCR (RT-IPCR) was developed for detection of pyrene and its homologs in water samples. The PAHs in sample compete with pyrene-modified DNA to bind with monoclonal antibody (McAb) coated on PCR plate. The reporter DNA was exponentially amplified by real-time PCR instrument using Fast Start universal SYBR Green Master (ROX) kit. Only two reaction steps were needed to accomplish the detection. The assay had a good linear range from 5 pmol L(-1) to 5 nmol L(-1) with a detection limit of 3.5 pmol L(-1). For application assay, the average recoveries from tap water, lake water and mineral water were 98.4%, 98.2% and 99.7%, respectively which showed a good correlation (R(2)=0.9906) with those from GC-MS. The results indicated that the improved RT-IPCR seems to be a potential method for simple and ultrasensitive detection of pyrene and some homologues in environment water samples.

Nanoporous Graphene with Single-Atom Nickel Dopants: An Efficient and Stable Catalyst for Electrochemical Hydrogen Production.

Single-atom nickel dopants anchored to three-dimensional nanoporous graphene can be used as catalysts of the hydrogen evolution reaction (HER) in acidic solutions. In contrast to conventional nickel-based catalysts and graphene, this material shows superior HER catalysis with a low overpotential of approximately 50 mV and a Tafel slope of 45 mV dec(-1) in 0.5 M H2SO4 solution, together with excellent cycling stability. Experimental and theoretical investigations suggest that the unusual catalytic performance of this catalyst is due to sp-d orbital charge transfer between the Ni dopants and the surrounding carbon atoms. The resultant local structure with empty C-Ni hybrid orbitals is catalytically active and electrochemically stable.

Gamma-glutamyl transpeptidase level is a novel adverse prognostic indicator in human metastatic colorectal cancer.

AIM: Biomarkers have been utilized for prognosis in colorectal cancer; however, relatively few have been identified. We compared the prognostic value of serum alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and gamma-glutamyl transpeptidase (GGT) with carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) in patients with metastatic colorectal cancer (mCRC). METHOD: Blood samples were collected from 239 patients with mCRC presenting between 2005 and 2010 in the Sun Yat-sen University Cancer Center. RESULTS: CEA (P < 0.001), CA19-9 (P < 0.001), GGT (P < 0.001), ALP (P < 0.001) and LDH (P = 0.001) were statistically significant prognostic factors of overall survival (OS). CEA (P = 0.002) and GGT (P = 0.021) were validated as independent predictors. On univariate analysis, CEA (P = 0.003), CA19-9 (P = 0.006), GGT (P < 0.001) and ALP (P = 0.001) were statistically significant predictive factors of progression-free survival (PFS) in patients having first-line chemotherapy. CEA (P = 0.011) and GGT (P = 0.027) were independent predictors. GGT (P = 0.001), ALP (P = 0.016) and LDH (P = 0.039) levels were correlated with the tumour response rate assessed by CT, whilst CEA (P = 0.724) and CA19-9 (P = 0.822) were not. There was a statistically significant difference in OS (P < 0.001) and PFS (P < 0.001) among patients who had elevations of both CEA and GGT compared with those in whom only one or neither was elevated. CONCLUSION: Among GGT, LDH and ALP, only GGT plays an independent role with CEA in predicting OS and PFS in mCRC. When coupled with CEA, GGT may lead to improved prognostic predictors.

Highly virulent porcine reproductive and respiratory syndrome virus emerged in China.

A highly pathogenic pig disease emerged in China in 2006, which was characterized by prolonged high fever, red discoloration of the body, and blue ears associated with high mortality. Porcine reproductive and respiratory syndrome virus (PRRSV) was isolated as the single most prominent virus in the samples collected from affected pigs. The full-length genomic sequence of the virus revealed two distinct deletions in the non-structural protein 2 (NSP2) in comparison to all previously reported North American genotype PRRSV. Through extensive surveys in 14 different provinces, 56 additional PRRSV isolates were obtained from affected farms. All of the isolates were found to contain identical deletions in NSP2. To confirm the etiology, eight 60-day-old PRRSV-free pigs were divided into two groups and the test group was intranasally infected at a titer of 2 x 10(5.0) tissue culture infectious dose 50 per pig. The inoculated pigs all died at 7, 8, 12, 16, or 21 days post-inoculation with their clinical and pathological findings similar to those in the field. The viruses recovered from dead pigs were identical to the inoculated virus in NSP2 and GP5 genes. Our study shows that the recently emerged PRRSV in China is characterized by two discontiguous deletions in NSP2 and is the cause for the current epizootics in China.