Pulmonary alveolar microlithiasis combined with gastric mucosal calcification: a case report.

Background: Pulmonary alveolar microlithiasis (PAM) is a rare disease whose clinical and imaging manifestations are non-specific, characterized by the deposition of microliths, which primarily consist of calcium and phosphorus, within the alveoli. In the cases of PAM, patients combined with calcification of other organs such as gastric mucosal calcification are less common. Case presentation: A 59-year-old woman was admitted to our hospital due to cough producing white, foamy sputum, accompanied by dyspnea and fever for 20 days. The CT scan showed diffuse ground-glass opacities and calcification of the gastric mucosa. Lung tissue biopsy revealed the presence of calcification and granulomatous foreign bodies in the interstitium and alveolar cavity. In the later stages, she developed painful skin petechiae. For this patient, the diagnosis of PAM, gastric mucosal calcification, and purpura fulminans was made. However, the genetic test results hinted that the patient and her son had a heterozygous mutation in the FBN1 gene, but her daughter's genetic test results were normal. Although the patient received anti-infection treatment, steroids, and oxygen therapy, her condition did not improve. Conclusion: We reported a rare case of PAM combined with calcification of other organs and purpura fulminans. Treatment of steroids did not show any benefit. The causative mechanism and effective treatment of this disease remain unclear. More treatments need to be explored.

What shapes people's willingness to wear a face mask at the beginning of a public health disaster? A qualitative study based on COVID-19 in China.

COVID-19 should not be the world's last public health disaster, so there is an urgent need to learn from COVID-19 to prepare better for the next public health disaster. This study aims to understand the factors that make people wear a face mask at the beginning of an outbreak of public health disaster. Semi-structured interviews were conducted during April 2020 in China, one month after the COVID-19 was declared a pandemic. The respondents were members of the public living in China, covering two age groups: young adults and older adults. They were recruited using a convenient sample and snowball sampling strategy. The results were analysed using content analysis. Seventeen subjects were recruited, among which nine were young adults (average age = 26.4; SD = 10.5), and eight were older adults (average age = 60.4; SD = 12.1). This study found that environmental factors, personal factors, factors concerning wearing masks, specific circumstances, and development of the pandemic were the common factors considered by both young adults and older adults. This study should help the authority formulate prevention policies better to reduce the risk of an outbreak if there is a new virus outbreak in the future, unfortunately.

Population pharmacokinetic analysis of tacrolimus early after Chinese pediatric liver transplantation.

OBJECTIVE: The purpose of this study was to describe the population pharmacokinetics (PK) of tacrolimus (TAC) in 52 Chinese pediatric patients early after liver transplantation. METHODS: Details of drug dose, sampling times and concentrations were collected retrospectively from routine therapeutic drug monitoring data from the first day after surgery. A total of 488 concentration data were obtained and analyzed by a nonlinear mixed-effect modeling (NONMEM) method. A number of demographic and clinical variables were tested for their influence on TAC PK parameters. RESULTS: The PK of TAC were best described by a one-compartment model with first-order absorption and elimination. Apparent clearance (CL/F) and apparent volumes of distribution (V/F) in final population model were 5.72 L/h and 131 L, respectively. The absorption rate constant (Ka) was fixed in 4.48 h-1. The inter-individual variabilities in CL/F and V/F were 13.5% and 78.1%. In the final analysis performed in all 52 patients, the post-operation day (POD) and alanine aminotransferase (ALT) influenced TAC CL/F and V/F, and total protein (TP) was the only covariate retained on V/F. CONCLUSION: A population PK model of TAC was developed in Chinese pediatric patients early after liver transplantation. It identified significant relationships between the PK of TAC and the characteristics of the patients. POD, ALT, and TP were identified as the main factors influencing the PK of TAC. The developed model could be useful to optimize individual pediatric TAC dosing regimen in routine clinical practice.

[Food security in 'Grain for Green Project' area of North Shaanxi based on households].

This paper analyzed the food production by the households in the counties with high population (Mizhi County) and low population (Wuqi County) in North Shaanxi, and studied the food security and its affecting factors in the two counties by using minimum cropland area per capita and Cobb-Douglass production function methods. The results demonstrated that the food production in low population county could meet the basic standard of food security, while that in high population county could not. Cultivated area and investment in agricultural technology were the major factors affecting food security; labor force, labor quality, and grain subsidy also had positive effects on food production. The current technology and labor quality did not reach their potential for food production. This region needed to increase grain production area to reach the minimum standard of 0.14 bm2 per capita, put much stress on labor force training, and formulate appropriate following policies for 'Grain for Green' to realize the food security strategy.

[Ecological cost of grain production in gully area of Loess Plateau].

Economic and ecological methods were applied to investigate the ecological cost of grain production in the gully area of Loess Plateau. In the study area in 2008, the ecological loss due to grain production was 7.2% of the total crop output, and the ecological cost reached 2.42 yuan x kg(-1) for wheat and 2.12 yuan x kg(-1) for corn. However, the per unit sales were 1.70 yuan x kg(-1) for wheat and 1.28 yuan x kg(-1) for corn. The combination of high production cost and low income affected the sustainable development of local ecological economy. The analysis of grey relationships among various factors affecting the ecological cost of grain production indicated that yield, sown area, and agricultural mechanical cost were the important factors affecting the ecological cost of grain production, while chemical fertilizer cost and organic fertilizer cost had less impact on the ecological cost of grain production. Under current production conditions, the ecological cost of grain production in the area could be reduced by raising the level of scientific and technological inputs, expanding the scale of family agricultural production, and improving the grain yield.

Molecular simulation of adsorption and separation of mixtures of short linear alkanes in pillared layered materials at ambient temperature.

Grand canonical Monte Carlo and configurational-bias Monte Carlo techniques are carried out to simulate the adsorption of ternary and quaternary mixtures of short linear alkanes, involving methane, ethane, propane, and n-butane, in pillared layered materials at ambient temperature, T=300 K. In the simulation, a pillared layered pore is modeled by a uniform distribution of pillars between two layered walls built by making two separate talc lamellas parallel each other with a given size of interlayer distance. The interaction between fluid molecules and two layered walls is measured by storing potentials calculated in advance at a series of grid points. The interaction between fluid molecules and pillars is also calculated by a site-to-site method. The potential model proposed in this work is proved to be effective because of the simulation result being good agreement with the experimental data for the adsorption of nitrogen at 77 K. Then, the adsorption isotherms of mixtures of short linear alkanes in pillared layered pores with three different porosities psi=0.98, 0.93 and 0.85, and three pore widths H=1.02, 1.70 and 2.38 nm at 300 K are obtained by taking advantage of the model. The simulation results tell us that the longer chain component is preferentially adsorbed at low pressures, and its adsorption increases and then decreases as the pressure increases while the shorter chain component is still adsorbed at high pressures. Moreover, the sorption selectivity of pillared layered materials for the longest chain component in alkane mixtures increases as the mole fraction of methane in the gas phase increases. The selectivity of pillared layered materials for the longest chain component in alkane mixtures also increases as the pore width decreases and the porosity increases.