A simple transmission dynamics model for predicting the evolution of COVID-19 under control measures in China.

Epidemic forecasting provides an opportunity to predict geographic disease spread and counts when an outbreak occurs and plays a key role in preventing or controlling their adverse impact. However, conventional prediction models based on complex mathematical modelling rely on the estimation of model parameters, which yields unreliable and unsustainable results. Herein, we proposed a simple model for predicting the epidemic transmission dynamics based on nonlinear regression of the epidemic growth rate and iterative methods, which is applicable to the progression of the COVID-19 outbreak under the strict control measures of the Chinese government. Our model yields reliable and accurate results as confirmed by the available data: we predicted that the total number of infections in mainland China would be 91 253, and the maximum number of beds required for hospitalised patients would be 62 794. We inferred that the inflection point (when the growth rate turns from positive to negative) of the epidemic across China would be mid-February, and the end of the epidemic would be in late March. This model is expected to contribute to resource allocation and planning in the health sector while providing a theoretical basis for governments to respond to future global health crises or epidemics.

Population genetic diversity of an odorous frog Odorrana grahami (Amphibia: Anura: Ranidae) in relation to conservation based on mitochondrial DNA.

The diskless-fingered odorous frog Odorrana grahami is widely distributed in the high-altitude mountains in the southwestern China and northern Indochina regions. In this study, a comparative analysis of the mitochondrial COI gene sequences was performed to examine the population genetic diversity of 76 individuals from 10 localities across the distributional range of the species. Haplotype diversity and nucleotide diversity were 0.605 and 0.00199, respectively, in the total population. An AMOVA indicated that 47.3% of the total variation originated from variation within individual populations and 52.7% came from variation between the 10 geographic populations. Tests of neutral evolution indicated that a recent expansion occurred in total population. The findings provide useful information for the conservation of this species.

Assessment of fine-scale parameterizations at low latitudes of the North Pacific.

Fine-scale parameterizations based on shear and stratification are widely used to study the intensity and spatial distribution of turbulent diapycnal mixing in the ocean. Two well-known fine-scale parameterizations, Gregg-Henyey-Polzin (GHP) parameterization and MacKinnon-Gregg (MG) parameterization, are assessed with the full-depth microstructure data obtained in the North Pacific. The GHP parameterization commonly used in the open ocean succeeds in reproducing the dissipation rates over smooth topography but fails to predict the turbulence over rough topography. Failure of GHP parameterization over rough topography is attributed to the deviation of internal wave spectrum from the Garrett-Munk (GM) spectrum. The internal wave field over rough topography is characterized by energetic intermediate-scale and small-scale internal waves that are not described well by the GM model. The MG parameterization that is widely used in coastal environments is found to be successful in reproducing the dissipation rates over both smooth and rough topographies. The efficacy of GHP and MG parameterizations in evaluating the dissipation rates has been assessed. The result indicates that MG parameterization predicts the magnitude and variability of the dissipation rates better than the GHP parameterization.

Synergistic effect of α-glucosidase inhibitors and dipeptidyl peptidase 4 inhibitor treatment.

Monotherapy of α-glucosidase inhibitor (α-GI) or dipeptidyl peptidase 4 (DPP4) inhibitor does not sufficiently minimize glucose fluctuations in the diabetic state. In the present study, we evaluated the combined effects of various of α-GI inhibitors (acarbose, voglibose or miglitol) and sitagliptin, a DPP4 inhibitor, on blood glucose fluctuation, insulin and active glucagon-like peptide-1 (GLP-1) levels after nutriment loading in mice. Miglitol and sitagliptin elicited a 47% reduction (P < 0.05) of the area under the curve of blood glucose levels for up to 2 h after maltose-loading, a 60% reduction (P < 0.05) in the range of blood glucose fluctuation, and a 32% decrease in plasma insulin compared with the control group. All three of the combinations elicited a 2.5-4.9-fold synergistic increase in active GLP-1 (P < 0.05 vs control). Thus, combined treatment with the α-GI miglitol, which more strongly inhibits the early phase of postprandial hyperglycemia, and DPP4 inhibitor yields both complementary and synergistic effects, and might represent a superior anti-hyperglycemic therapy. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2010.00081.x, 2011).

[An optoelectronic cervical cancer screening system for screening cervical cancer: comparison with cervical cytology].

OBJECTIVE: To study the clinical value of optoelectronic cervical cancer screening system (TruScreen, TS) in the screening of cervical cancer in comparison with cervical cytology test. METHODS: A total of 392 patients were screened by TS, Pap, TCT, and HPV using the pathological and colposcopical results as the golden standard. The sensitivity, specificity, Kappa value and the area of under ROC of each method and their combinations (parallel tests) were compared. RESULTS: The sensitivity of TS, Pap, TCT and HPV were 32.2%, 42.2%, 74.4% and 47.8%, with specificity of 96.7%, 93.7%, 78.8% and 84.8% in detecting cervical cancer, respectively. The sensitivity of the parallel tests, namely TCT/HPV, TCT/TS, Pap/TS and HPV/TS were 65.6%, 87.8%, 82.2% and 86.7%, with the specificity of 81.1%, 74.5%, 75.8% and 67.2%, respectively. In light of the areas of under ROC, significant differences were noted between the parallel tests of TS/Pap and TS/TCT (P<0.05), but not between TCT/Pap and TCT/TS (P>0.05); significant differences were found between the parallel tests with TS and those without TS (P<0.05), but not between TS alone and the parallel tests incorporating TS (P>0.05), nor between the 4 parallel tests (P>0.05). CONCLUSION: As a new modality for early screening of cervical carcinoma, TS offers a means for real-time cancer detection with better diagnostic efficacy than Pap and HPV and equivalent efficacy to TCT. The combination of TS and cytological tests can further enhance the diagnostic accuracy.