[Investigation on diagnosis of pneumoconiosis in non-coal mining industry in Jiangsu Province]

Objective: To understand the incidence of pneumoconiosis in the non-coal mining industry in Jiangsu Province, and provide reference for the prevention and control of pneumoconiosis in the non-coal mining industry. Methods: The data of 7019 newly diagnosed pneumoconiosis patients in non-coal mining industry in Jiangsu Province from January 1956 to December 2019 were collected through the Jiangsu Province Pneumoconiosis Follow-up Network Report System, including the gender of the pneumoconiosis patients, the name of the employer and the location, the industry classification of the employer, the duration of dust exposure in dust exposure, the name of occupational pneumoconiosis disease, the date of diagnosis of pneumoconiosis, etc. The collected case data of patients with pneumoconiosis were entered into the statistical software, and the characteristics of the patients' diagnosis time, region and industry were analyzed. Results: The number of confirmed pneumoconiosis patients in the non-coal mining industry in Jiangsu Province was mostly in 2007 (395 cases) , concentrated in Wuxi City (40.96%, 2875/7019) and Suzhou City (27.72%, 1946/7019) . The industries to which the patients belonged were mainly non-metallic mining and dressing (60.95%, 4278/7019) , and the most common type of pneumoconiosis was silicosis (96.40%, 6766/7019) . The patients were mainly stageⅠpneumoconiosis (61.33%, 4305/7019) . There were statistically significant differences in the mean age of diagnosis and the average duration of dust exposure among patients with different pneumoconiosis stages (P<0.01) . The differences in the average diagnosis age and the average duration of dust exposure of patients with different types of pneumoconiosis were statistically significant (P<0.05) , the mean age of diagnosis and the average duration of dust exposure of electric welders were the smallest, which were (44.92±7.74) years old and (17.38±10.15) years, respectively. Conclusion: The regional and industry distribution characteristics of new pneumoconiosis patients in the non-coal mining industry in Jiangsu Province are obvious, and attention should be paid to the treatment of pneumoconiosis patients with young diagnosed age and short duration of dust exposure, as well as the personal protection and health protection of front-line workers such as electric welders who are exposed to productive dust in a short period of time.

Validation of finger test for necrotising soft tissue infection

Background:

Necrotising soft tissue infection (NSTI) is rare but fatal. Andreasen proposed finger test as an early diagnostic tool to differentiate NSTI from other soft tissue infections. We aim to evaluate the accuracy and reproducibility of the test for the diagnosis of NSTI.

Methods:

Patients who were admitted to our department from 2012 to 2016 with suspicion of NSTI and finger test done were retrospectively reviewed. Finger test was done and interpreted as described by Andreasen. Definitive diagnosis of NSTI was confirmed with surgical and pathological findings.

Results:

Among the 35 patients included in the study, NSTI was confirmed in 10 cases. Finger test had a sensitivity of 100%, a specificity of 80%, positive predictive value of 66.7%, negative predictive value of 100% and an overall accuracy of 85.7%. There was no difference in demographics or comorbidities between NSTI and non-NSTI groups. Surgeons involved had 76.7% agreement and moderate reproducibility (kappa = 0.48) on the diagnostic criteria of finger test.

Conclusion:

A negative finger test was reliable to exclude NSTI and a positive test suggested further surgical exploration. Yet, clinical judgement was still of paramount importance to treat NSTI promptly.

Single-molecule imaging of DNA polymerase I (Klenow fragment) activity by atomic force microscopy

We report a DNA origami-facilitated single-molecule platform that exploits atomic force microscopy to study DNA replication. We imaged several functional activities of the Klenow fragment of E. coli DNA polymerase I (KF) including binding, moving, and dissociation from the template DNA. Upon completion of these actions, a double-stranded DNA molecule was formed. Furthermore, the direction of KF activities was captured and then confirmed by shifting the KF binding sites on the template DNA.

Visualizing dopamine released from living cells using a nanoplasmonic probe

We report the development of an ultrasensitive nanoplasmonic probe for discriminative detection and imaging of dopamine released from living cells. The sensing mechanism is based on the dopamine-induced seeded-growth of Au nanoparticles (Au NPs) that leads to the shift of the plasmon band. This platform allows for the detection of dopamine with a detection limit down to 0.25 pM within 1 min. This nanoplasmonic assay is further applied to visualize the release of dopamine from living rat pheochromocytoma (PC12) cells under ATP-stimulation with dark-field microscopy (DFM). The DFM results together with real time fluorescence imaging of PC12 cells stained with the Fluo calcium indicator, suggested that ATP stimulated-release of dopamine is concomitant with the Ca(2+) influx, and the influx of Ca(2+) is through ATP-activated channels instead of the voltage-gated Ca(2+) channel (VGC).

Nanocrystalline silicon-based oligonucleotide chips

A novel oligonucleotide array sensor has been developed with nanocrystalline Si (ncSi) substrates. The ncSi was prepared by electrochemical etching technique. Our study indicated that both the binding capacity and the hybridization efficiency are dependent upon the particle size of ncSi. In contrary, the chips developed with Si substrates exhibit the lower binding capacity and hybridization efficiency. The improved performances of the sensor chips are attributed to the large specific surface area of ncSi compared to the existing conventional techniques. The sensor chips with the ncSi substrate of 13 nm-sized particle can be regenerated and reused for at least 12 times. The oligonucleotide array sensor also shows high stability, which can bear relatively the stringent conditions (e.g. 80 degrees C, 75% of relative humidity and 3.6 klx of irradiation).

Photo-induced cytotoxicity of malonic acid [C(60)]fullerene derivatives and its mechanism

The biological activities of fullerenes have attracted extensive attention in recent years. The aim of this paper is to study the relation of the photo-induced cytotoxicity of fullerene derivatives to their chemical structures as well as the possible cellular mechanism involved in the photocytotoxicity. Three C(60) derivatives with two to four malonic acid groups (DMA C(60), TMA C(60) and QMA C(60)) were prepared and the cytotoxicity of these compounds against HeLa cells was determined by MTT. Cell cycle was measured by flow cytometry. The results showed that the cytotoxicity of the malonic acid C(60) derivatives was irradiation- and dose-dependent. The sequence of their photo-induced growth inhibition was DMA C(60)>TMA C(60)>QMA C(60). Hydroxyl radical quencher mannitol (10mM) was not able to prevent cells from the damage induced by irradiated DMA C(60). DMA C(60), together with irradiation, was found to have an ability of inducing a decrease in the number of G(1) cells from 63 to 42% and a rise in that of G(2)+M cells from 6 to 26%. These data indicated that the number of malonic acid molecules added to C(60) played an important role in the phototoxicity, and the blockage of cell cycle might be a mechanism of this activity.

Modeling optical breakdown in dielectrics during ultrafast laser processing

Laser ablation is widely used in micromachining, manufacturing, thin-film formation, and bioengineering applications. During laser ablation the removal of material and quality of the features depend strongly on the optical breakdown region induced by the laser irradiance. The recent advent of amplified ultrafast lasers with pulse durations of less than 1 ps has generated considerable interest because of the ability of the lasers to process virtually all materials with high precision and minimal thermal damage. With ultrashort pulse widths, however, traditional breakdown models no longer accurately capture the laser-material interaction that leads to breakdown. A femtosecond breakdown model for dielectric solids and liquids is presented that characterizes the pulse behavior and predicts the time- and position-dependent breakdown region. The model includes the pulse propagation and small spatial extent of ultrashort laser pulses. Model results are presented and compared with classical breakdown models for 1-ns, 1-ps, and 150-fs pulses. The results show that the revised model is able to model breakdown accurately in the focal region for pulse durations of less than 10 ps. The model can also be of use in estimating the time- and position-resolved electron density in the interaction volume, the breakdown threshold of the material, shielding effects, and temperature distributions during ultrafast processing.

[Effect of covering the ground under canopy tree with straw on growth of dogwood (Cornus officinalis Sieb. et Zucc.)]

Experiments showed that the growth, blooming and bearing of dogwood (Cornus officinalis) were improved by covering the ground under canopy tree with straw. Growth of shoots, weight and thickness of 100 fresh leaves, and mineral nutrition of leaves were significantly higher than those of controls. Fruit buds of shoots, fruit setting per cluster, weight of 100 fresh fruits and yield per tree were increased by 17.9%, 20%, 31.7% and 33.5% respectively. Compared with uncovered trees, the blooming period of covered trees was delayed by 4-6 days.