Incidence trend of 2019 novel coronavirus diseases (COVID-19) in China / 上海预防医学

Objective To investigate the epidemical characteristics and analyze the incidence trend of 2019 novel coronavirus diseases (COVID-19) in China. Methods The daily new confirmed cases of 2019 COVID-19 in China from January 25 to February 8, 2020 were collected for epidemiological descriptive analysis. Results During the period from January 25 to February 8, 2020, the number of daily new confirmed cases fell for five consecutive days, from 890 cases on February 3 to 509 cases on February 8. Conclusion The incidence of COVID-19 slows down in 30 provinces (autonomous regions and municipalities directly under the central government) except Hubei and Xinjiang Production and Construction Corps, but the overall situation is still not optimistic.It is imperative to pay close attention to the origin and destination of migrant workers and the incidence of disease in various areas, and to take targeted measures to strengthen prevention and control of the disease.

Incidence trend of 2019 novel coronavirus diseases (COVID-19) in China / 上海预防医学

Objective To investigate the epidemical characteristics and analyze the incidence trend of 2019 novel coronavirus diseases (COVID-19) in China. Methods The daily new confirmed cases of 2019 COVID-19 in China from January 25 to February 8, 2020 were collected for epidemiological descriptive analysis. Results During the period from January 25 to February 8, 2020, the number of daily new confirmed cases fell for five consecutive days, from 890 cases on February 3 to 509 cases on February 8. Conclusion The incidence of COVID-19 slows down in 30 provinces (autonomous regions and municipalities directly under the central government) except Hubei and Xinjiang Production and Construction Corps, but the overall situation is still not optimistic.It is imperative to pay close attention to the origin and destination of migrant workers and the incidence of disease in various areas, and to take targeted measures to strengthen prevention and control of the disease.

Incidence trend of 2019 novel coronavirus diseases (COVID-19) in China / 上海预防医学

Objective To investigate the epidemical characteristics and analyze the incidence trend of 2019 novel coronavirus diseases (COVID-19) in China. Methods The daily new confirmed cases of 2019 novel coronavirus diseases (COVID-19) in China from January 25 to February 8,2020 were collected for epidemiological descriptive analysis. Results During the period from January 25 to February 8, 2020, the number of daily new confirmed cases fell for five consecutive days, from 890 cases on February 3 to 509 cases on February 8. Conclusion The incidence of 2019 novel coronavirus diseases (COVID-19) slowed down in 30 provinces (autonomous regions and municipalities directly under the central government) except Hubei and Xinjiang production and construction corps , but the overall situation is still not optimistic. It is imperative to pay close attention to the origin and destination of migrant workers and the incidence of disease in various areas, and take targeted measures to strengthen prevention and control of the disease.

Osteoblastic early attachment onto the surface of bioadhesive peptide modified pure titanium / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the long-term integrity and the biological function of interface between the bioadhesive peptide modified implant surface and peri-implant tissue.</p><p><b>METHODS</b>A short bioadhesive peptide containing Glycine-Tyrosine-Arginine-Glycine-Asparticacid-Serine (GYRGDS) sequence was immobilized onto the titanium implant surface by means of sol-gel coating technique and self-assembled monolayers (SAM). The chemical composition and organic functional groups on the titanium surfaces were characterized using XPS (X-ray photoelectron spectroscopy) and FTIR (Fourier transform infrared spectrometer). The adhesive strength and stability of osteoblasts on various implant surfaces were compared under flow condition.</p><p><b>RESULTS</b>The results showed that alkali/hot water aging treatment could apparently improve the content of -OH functional groups of titanium surface. The chemical reactive Ti-O-Ti bonding at the surface of titanium played a vital role in inducing the formation of organosilane SAM. GYRGDS peptide can be covalently grafted onto the surface of titanium by SAM technique. The resistance of freshly adherent osteoblasts to detachment by flow was shear time dependent. When the four groups were compared under the same flow stress condition (2.05 Pa) at three specific time spans (30 min, 1 h, 2 h), the cells retention rates in GYRGDS-grafted groups were 93.0%, 54.4%, 34.4% respectively and were much higher than those in non-coated groups.</p><p><b>CONCLUSIONS</b>It was suggested that GYRGDS might have positive effects on maintaining stability and adherence of cells onto the substrates under flow condition.</p>

Effects of Gukang on bone-source alkaline phosphatase (BALP) and insulin-like growth factor-1 (IGF-1) in serum of spaying rats / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the effects of Gukang on bone-source alkaline phosphatase (BALP) and insulin-like growth factor 1 (IGF-1) in serum of spaying rats and the mechanism of curative effect of Gukang on osteoporosis.</p><p><b>METHODS</b>Sixty-eight 6-month-old SD rats were chosen and randomly divided into blank control group (22 rats with sham operation) and operation group (46 rats with spaying operation). Three months after operation, 10 rats were randomly chosen from each group and tested with bone mineral density in order to determine models of osteoporosis made. After modeling, operation group was divided into 3 sub-groups: operation model group, estrogen group and Gukang group, 12 rars in each group. Twelve rats remained in blank control group. Every group were treated through intragastric administration therapy (volume 10 ml/kg). Blank control group and operation model group were irrigated with distilled water,estrogen group with estrogen and Gukang group with Gukang. Three months after treatment, serum of all groups were collected and tested for E2, BALP and IGF-1 with ELISA.</p><p><b>RESULTS</b>The concentration of serum E2, BALP in estrogen group and Gukang group were higher than operation model group, there were significant difference (P < 0.05), but no significant difference in serum E2 between estrogen group and Gukang group (P > 0.05). The concentration of serum IGF-1 in Gukang group was higher than operation model group and blank control group, there were significant difference (P < 0.05).</p><p><b>CONCLUSION</b>Gukang can increase the level of E2, BALP and IGF-1 in serum of spaying rats. Thus, it can indirectly promote reproduction of osteoblasts, inhibit activity of osteoclasts and promote bone formation.</p>

Modulation of leak K(+) channel in hypoglossal motoneurons of rats by serotonin and/or variation of pH value / 生理学报

The cloned TWIK-related acid-sensitive K(+) channel (TASK-1) is sensitive to the pH changes within physiological pH range (pK~7.4). Recently, the native TASK-1-like channel was suggested to be the main contributor to the background (or leak) K(+) conductance in the motoneurons of the brain stem. Serotonin (5-HT) and variation of pH value in perfused solution could modulate these currents. Here we aimed to examine the properties and modulation of the currents by serotonin or variation of pH value in hypoglossal motoneurons of rats. Transverse slices were prepared from the brainstem of neonatal Sprague-Dawley rats (postnatal days 7-8). Hypoglossal motoneurons were used for the study. The leak K(+) current (TASK-1-like current) and hyperpolarization-activated cationic current (I(h)) were recorded with the whole-cell patch-clamp technique. The results showed that these currents were inhibited by acidified artificial cerebrospinal fluid (ACSF, pH 6.0) and activated by alkalized ACSF (pH 8.5). 5-HT (10 mumol/L) significantly inhibited both leak K(+) current and I(h) with depolarization of membrane potential and the occurrence of oscillation and/or spikes. Bath application of Ketanserine, an antagonist of 5-HT₂ receptor, reversed or reduced the inhibitory effect of acidified solution on leak K(+) current and I(h). The results suggest that 5-HT₂ receptors mediate the effects of acidified media on leak K(+) current and I(h) in hypoglossal motoneurons.

Microwave sintering of nanometer powder of alumina and zirconia-based dental ceramics / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The objective of the present study was to investigate the feasibility and reliability of sintering alumina and zirconia-based all-ceramic materials through a recently introduced microwave heating technique. The variation of crystal phases, the growth of grain sizes and microstructural features of these materials were evaluated after sintering.</p><p><b>METHODS</b>Four different groups of powder (l00%Al2O3, 60%Al2O3+40%ZrO2, 40% Al2O3+60%ZrO2, 100% ZrO2) were respectively press-compacted to fabricate green disk samples, 5 specimen of each group were prepared. All the samples were surrounded by refractory materials for heat containment and processed at 1 600 degrees C in a domestic microwave oven (850 W, 2 450 MHz), 1 600 degrees C/5 min for heating rate, 10 min for holding time. After sintering, the phase composition and average grain size of these ceramics were examined using X-ray diffraction (XRD). Their microstructure characteristics were studied by scanning electron microscopy (SEM).</p><p><b>RESULTS</b>All the specimens were successfully sintered with the application of microwave heating system in combination with a suitable thermal insulator. No phase change was found in alumina while monoclinic-zirconia was found to be transformed to tetragonal-zirconia. A little grain size growth of Al2O3 and ZrO2 has been observed with Al2O3 24.1 nm/before and 51.8 nm/after; ZrO2 25.3 nm/before and 29.7 nm/after. The SEM photos indicated that the microwave-sintered Al2O3-ZrO2 ceramics had a uniform crystal distribution and their crystal sizes could be maintained within the range of nanometers.</p><p><b>CONCLUSION</b>It is expected that in the near future microwave heating system could be a promising substitute for conventional processing methods due to its unparalled advantages, including more rapid heating rate, shortened sintering time, superfine grain size, improved microstructure and much less expensive equipment.</p>