[Objective] To determine the sun protection factor (SPF) and protection factor of ultraviolet A (PFA) of a self-made sunscreen cream.[Methods] The sample of a self-made sunscreen cream and a commercial sunscreen cream were painted to an artificial skin (3M film) at a dose of 2 μl/cm2,and a tester was used to evaluate their photoprotective effect.A total of 48 albinism guinea pigs were classified into 8 groups to remain unprotected or be protected by the self-made or commercial sunscreen cream.A solar ultraviolet light simulator (SUV-1000) was used to simulate the ultraviolet rays in sunlight to irradiate the guinea pigs,and the photoprotecfive effect of these sunscreen creams was determined.[Results] The in vitro evaluation revealed that the SPF value of the self-made sun-screen cream and commercial cream was 32.26 ± 2.42 and 30.87 ± 2.57respectively (n =5,t =0.94,P ＞ 0.05),and the PFA value was 24.28 ± 2.44 and 17.53 ± 2.28 respectively (n =5,t =4.52,P＜ 0.01 ).As the in vivo experiment showed,the SPF value of the self-made sun-screen cream and commercial cream was 30.39 ± 6.65 and 28.79 ± 7.36,respectively (n =12,t =0.38,P＞ 0.05),and the PFA value was ＞ 8.91 and ＞ 8.93 respectively.[Conclusion] The photoprotective effect of the self-made sunscreen cream is similar to that of the commercial cream.

Oxygen enrichment of room air is an effective way to resist hypoxia at high altitude, but it may introduce a potential fire hazard. In common, the burning rate of light and thin homogeneous solid in oxygen enriched atmosphere was used to assess the fire hazard. For the purpose of measuring the burning rate of light and thin homogeneous solid in oxygen enriched atmosphere, we used the methods of laser contact ignition and direct calculation of burning rate, and invented a device that includes mixing gas system, ignition equipment, system of measuring the burning rate and self-made specimen frame. By using the homemade device, we studied the burning rate of filter paper under low pressure and in oxygen-enriched atmosphere and in that of the oxygen concentration of reached stationary burning rate. The results showed that this device was simple, and could obtain the burning rate of light and thin homogeneous solid quantitatively.
Air Pressure ; Altitude ; Atmosphere Exposure Chambers ; Environment, Controlled ; Equipment Design ; Fires ; prevention & control ; Oxygen ; analysis

OBJECTIVETo study the absorption mechanism of tanshinones in the roots of Salvia miltiorrhiza as well as the interaction between the components in the effective fraction.

METHODThe model of intestinal absorption in vivo was used and the concentrations of the tanshinones were determined by HPLC, the apparent absorption constant (K(a)) and half life of absorption (t1/2) were obtained, the other components in the extract on the absorption of the there components were also studied.

RESULTWith the increase of dosage of tanshinone II A or cryptotanshinone, K(a) decreased and absorption half life t1/2 increased, the drug absorption rate constant (K(a)) had little significant effect on duodenum, Jejunum and ileum. Tanshinone I has a good absorbing in the rat small intestine. The absorption of tanshinone II A and cryptotanshinone was promoted by the other components in tanshinones extract while tanshinone I' was decreased.

CONCLUSIONWhen the concentration increases to a certain level, the uptake of tanshinone II A and cryptotanshinone do not increase. The transport mechanism of tanshinone II A and cryptotanshinone in vivo is similar to active transport or facilitated diffusion. They could be well absorbed in general intestinal tract without specific absorption site, and the complex constituents in extract could significant effect the absorption of the pharmaceutical effective constituents.

Absorption ; Animals ; Diterpenes, Abietane ; Drugs, Chinese Herbal ; analysis ; pharmacokinetics ; Intestine, Small ; drug effects ; physiology ; Male ; Phenanthrenes ; analysis ; pharmacokinetics ; Rats ; Rats, Sprague-Dawley ; Salvia miltiorrhiza ; chemistry

Objective To verify the reliability of our previously established reverse-transcription loop-mediated isother-mal amplification ( RT-LAMP) method for the detection of sentinel lymph nodes metastasis in breast cancer patients .Meth-ods Sentinel lymph nodes of breast cancer patients were analyzed by RT-LAMP and FDA-approved GeneSearch methods respectively, and the consistency of the two methods was assessed with a kappa concordance test.Results One hundred and thirty-four cases of sentinel lymph node samples were collected from seven hospitals in Beijing .Using the GeneSearch assay as the gold standard, the sensitivity, specificity and consistentcy of RT-LAMP were 96.2%(25/26),96.3%(104/108) and 96.3%(129/134), respectively.Statistical analysis showed that the two methods were consistent (Kappa=0.8857, P<0.001).Conclusion RT-LAMP is highly consistent with GeneSearch ,efficient,simple and inexpensive, promising a good prospect of application to intra-operative detection of sentinel lymph nodes metastasis for breast cancer patients.

Objective To investigate the efficacy and safety of intravenous thrombolysis with low-dose and standard-dose recombinant tissue plasminogen activator(rt-PA)in the elderly patients(aged over 80 years)with acute ischemic stroke(AIS).Methods A total of 201 elderly patients with AIS treated at Tianjin Fourth Central Hospital from February 2019 to February 2023 were prospectively included and randomly assigned to the rt-PA low-dose group(n=93,0.6 mg/kg)and rt-PA standard-dose group(n=108,0.9 mg/kg).The incidence of intra-cranial hemorrhage,symptomatic intracranial hemorrhage,fatal intracranial hemorrhage,neurologic deterioration within 7 days and mortality within 90 days were observed to evaluate the safety.The neurologic improvement rate and good prognosis rate at 90 days were used to evaluate the effectiveness.A stratified analysis of 90-day outcomes was performed based on stroke severity and age.Results The incidence of intracranial hemorrhage,symptomatic intracranial hemorrhage and fatal intracranial hemorrhage within 7 days in rt-PA low-dose group was lower than that in rt-PA standard-dose group(P＜0.05).There were no statistically significant differences between the two groups concerning the residual safety index and the effectiveness index.The 90-day good prognosis rate of moderate stroke sub-group and of≥90 years of age sub-group in rt-PA low-dose group were both higher than that of rt-PA standard-dose group(P＜0.05).Conclusions For AIS patients with moderate stroke and aged over 90 years,intravenous thrombolytic therapy with rt-PA 0.6 mg/kg is recommended.

Objective: To investigate the effect of restraint stress on masseter mechanical hyperalgesia and the activity of neurons and astrocytes in the spinal trigeminal nucleus caudalis (Vc). Methods: The animals were randomly divided into the control group, 1-, 3-, 5-, 7-, 9-, 11-and 14-day stress groups, with 10 rats in each group. The body weight increase and behavior tests were used to testify the animal model. The mechanical sensitivity of masseter of the rat before and after the stress was measured with Von Frey filaments. Histological examinations were used to evaluate the expression of neuronal c-fos and astrocytic glial fibrillary acidic protein (GFAP). Results: Restraint stress resulted in remarkable mechanical allodynia in the masseter muscle. The head withdrawal threshold was significantly lower in the 7-, 9-, 11-and 14-day stress groups ([0.071±0.011], [0.059±0.020], [0.052±0.011], [0.033±0.011] N) than that in the control group ([0.120±0.025] N) (P<0.05). Compared to the control group, the rats in the 1-day stress group showed a significant increase of c-fos in neurons of the Vc and then declined to normal level after 1 week gradually. The GFAP expression in astrocytes of the Vc was significantly increased in the 7-, 9-, 11-and 14-day stress groups (4.3±1.0, 4.5±0.6, 4.6±0.5, 4.8±1.3) compared with the control group (2.0±0.8) (P<0.05). Conclusions Chronic restraint stress could lower the threshold of mechanical allodynia in the masseter muscle and activate the neurons and astrocytes in Vc. The activation of neurons and astrocytes plays an important role in the masseter hyperalgesia induced by restraint stress in rats.