Objective:To observe the elimination of smear layer on the dentin exposed to Er,Cr:YSGG laser with different energy and irradiating distance. Methods:The in vitro first premolar was selected and slices with 1.5 mm thickness were obtained by horizontal sectioning through the middle third of the teeth crown using a high-speed bur. Each dentinal slice was irradiated under the laser with different irradiating distance(

Objective To investigate the apoptosis induction effect of recombinant caspase-3 expression on osteosarcoma cell line SOSP-9901. Methods Recombinant caspase-3 gene was subcloned into the GFP reporter vector pEGFP-C1 to generate the expression vector pEGFP-caspase-3 by DNA recombinant technique. pEGFP-caspase-3 was transfected into human osteosarcoma cell line SOSP-9901 by Lipofectamine 2000. The expression of recombinant caspase-3 was determined by RT-PCR. The morphological changes of transfected cells were observed under flurescent and electronic microscope. The cell survival rate of transfected cells was assayed by MTT method. Results Recombinant caspase-3 gene could be stably expressed in the transfected SSOP-9901 cells. Recombinant caspase-3 could obviously induce SOSP-9901 apoptosis, and inhibit SSOP-9901 cell proliferation in vitro. Conclusion Recombinant caspase-3 could inhibit the growth of the osteosarcoma cell line SOSP-9901 and induce it into apoptosis.

Objective To investigate the effect of acute high intracranial pressure on the static pressure-volume curve of dogs' total respiratory system in order to evaluate the relationship between brain injury and respiratory insufficiency.Methods Fourteen dogs were divided into two groups.Animals were anesthetized,paralyzed and mechanical ventilated.The intracranial hypertension in experimental group(n=8)was induced by injecting blood-clots into the right frontal lobe.The other six dogs served as control.The intracranial pressure was monitored by an optical fiber transmitter inserted into the left cerebral hemisphere.The pressure-volume curves of the respiratory system were measured before and after induction of high intracranial pressure by a self-made apparatus consisting of two sealed bottles and a U shaped glass tube.The curves were also measured correspondingly in control group.The static compliance was calculated by equation C=?V/?P.The volume of intracerebral hematoma was calculated.The histopathology of lung was studied under microscope.Results The intracerebral hematoma was located in the right frontal lobe with volume from 4.8-11.5ml(average 8.48ml).The intracranial pressure was elevated from 18.13?5.96mmHg to 46.88?16.42mmHg,which induced a shift of pressure-volume curve to the right in experimental group,while no obvious change was found in control group.Compared to pre-injection,the static compliance of total respiratory system decreased significantly(P

Objective To observe the surface morphology of dentin irradiated by Er,Cr∶YSGG laser under anhydrous conditions and discuss the possible clinical applications of the laser.Methods 11 freshly extracted specimens (approximately 1.5 mm thick) taken from the first premolars were selected.One was regarded as the control group without any treatment and the remaining ten were divided into 5 groups whose dentin surface was irradiated by Er,Cr∶ YSGG laser with different energy (1,2,3,4,6 W) under anhydrous condition.The specimens were routinely prepared for electron microscopic scanning observation.Results As the output power increased with Er,Cr∶YSGG laser irradiation,the dentin surface was observed of the constriction of tubular lumen,and part of the tubules closed.The dentin surfaces with 3 ～6 W laser irradiation were observed thermal injury alters such as micro crack and carbonization.Conclusion 1 ～2 W anhydrous Er,Cr:YSGG laser irradiation play a more ideal and safe constriction and sealing role to dentinal tubules,and the laser is expected to be used for the treatment of dentin hypersensitivity.

Objective Face-down positioning after vitrectomy and gas tamponade is still the standard position for patients with rhegmatogenous retinal detachment.The study was to compare the nursing effects of face-down position and flexible position after vitrecto-my for the repair of rhegmatogenous retinal detachment. Methods We investigated 120 cases of patients with rhegmatogenous retinal detachment in this study.All patients received vitrectomy with long-acting gas for tamponade, 60 patients in face-down position and 60 in the flexible position.Patients were followed up for 6 months.Observation was made on the rates of anatomical retinal reattachment and postoperative complications between the groups. Results The rates of anatomical retinal reattachment after surgery were 88.33%in the face-down position group and 100% in the flexible position group respectively.As to the satisfaction of position, the flexible position group was 100%, which was much higher than 41.67%in face-down position group(P<0.01). Conclusion Flexible position nurs-ing after vitrectomy and gas tamponade for rhegmatogenous retinal detachment repair is safe and effective.Flexible position can replace face-down position for the comfort of patients with rhegmatogenous retinal detachment after vitrectomy with gas tamponade.

Child ; Child, Preschool ; Computer Systems ; Humans ; Phylogeny ; Polymerase Chain Reaction ; methods ; Respiratory Syncytial Viruses ; genetics ; isolation & purification ; Reverse Transcriptase Polymerase Chain Reaction ; methods

Objective: To enhance the percutaneous absorption of puerarin, a water insoluble drug, using microneedle-assisted microemulsion. Methods: With puerarin microemulsion as control, in vivo and in vitro experiments were conducted to evaluate permeation amount of puerarin, which was increased by 12.4 times using microneedle-assisted microemulsion. In rat skin microdialysis experiments in vivo, the peak concentration (Cmax) of puerarin in reception medium was (713.51 ± 72.23) ng/mL for microneedle-assisted microemulsion group and (108.56 ± 5.72) ng/mL for microemulsion group; The areas under concentration-time curves (AUCs) of puerarin were (5 021.45 ± 547.09) ng∙h/L for microneedle-assisted microemulsion group and (622.36 ± 41.21) ng∙h/L for microemulsion group, respectively. Compared with microemulsion, the Cmax and AUC of puerarin in rat skin microdialysis experiments in vivo were increased by 5.57 times and 7.07 times, respectively, when microneedle-assisted microemulsion was used. In pharmacokinetic experiments in rats, the Cmax and AUC of puerarin in rat plasma were (234.35 ± 25.02) ng/mL and (3 047.13 ± 486.51) ng∙h/L for the microneedle-assisted microemulsion group. The puerarin concentration in rat plasma for the microemulsion group were lower than the limit of detection. Conclusion: The transdermal absorption of puerarin could be enhanced obviously using microneedle-assisted microemulsion. By conducting this research, a preliminary foundation is laid for the development of novel delivery systems for puerarin.

OBJECTIVE: To investigate the relationship between pure-tone average (PTA), the fractional anisotropy (FA) of the auditory pathway, cognitive cortex and auditory cortex in presbycusis. METHOD: Twenty-five elderly subjects with presbycusis were participated in the study. PTA, speech discrimination abilities were evaluated in each subject. Diffusion tensor imaging (DTI) was applied to access the FA of the IC, the superior frontal gyrus and the Heschl's gyrus. Compare the difference between two sides of the values of FA in the three areas. Bivariate correlation analysis was performed to evaluate the effects of PTA and FA of the inferior colliculus (IC), the superior frontal gyrus and the Heschl's gyrus on speech discrimination abilities. RESULT: There were no significant differences between the left and right side of the inferior colliculus (P > 0.05). Higher FA values were recorded at the left side of the Heschl's gyrus and the superior frontal gyrus (P < 0.05). Both PTA and the FA of the superior frontal gyrus have a negative association with speech discrimination abilities (P < 0.01, P < 0.05), while the FA of the Heschl's gyrus has a positive association with speech discrimination abilities (P < 0.05). CONCLUSION Our findings indicated that the speech discrimination abilities of the elderly is not only related to the peripheral auditory function, but also to the central auditory and cognitive function.
Aged ; Audiometry, Pure-Tone ; Auditory Cortex ; physiopathology ; Auditory Pathways ; Diffusion Tensor Imaging ; Humans ; Inferior Colliculi ; physiopathology ; Presbycusis ; diagnosis ; Speech Perception

Cancer is considered as one of the major diseases endangering human health in the world, it is urgent to find a safer and more efficient treatment for cancer therapy. Gene therapy with ribonucleic acid (RNA) drugs could regulate the expression of tumor related genes, and exhibit good anti-tumor therapeutic potential in preclinical and clinical trials. Based on the differences between tumor tissues and normal tissues in microenvironment signal characteristics such as pH, specific enzyme concentration or redox gradient, various microenvironment responsive nanocarriers had been studied and developed to deliver RNA drugs to tumor tissues and cells, improving the anti-tumor efficacy of RNA drugs and reducing toxic and side effects. This paper reviews the pathophysiological characteristics of tumor microenvironment and various strategies of tumor microenvironment responsive nanocarriers, in order to provide reference for the design of safe and efficient RNA drug delivery system for cancer therapy.

Objective: To establish a method to determine 4 active ingredients in Jindan tablets by HPLC.
Methods: Agilent Eclipse X DB C₁₈ (4.6 mm×250 mm, 5 μm) column was adoped using acetonitrile (phase A) -0.1% phophoric acid solution (phase B) as the mobile phase with gradient program at the flow rate of 1.0 mL·min^-1, the detection wavelength was 270 nm, Column temperature was set at 30 ℃.
Results: The linear ranges of gentiopicrin, polydatin, quercetin and emodin were 7.875-78.75 μg·mL^-1（r=0.999 9）, 6.75-67.50 μg·mL^-1（r=0.999 7）, 7.726-77.26 μg·mL^-1（r=0.999 4）, 3.809-38.09 μg·mL^-1（r=0.999 8), respectively, the peak area had a good linear relationship with the mass concentration of 4 components, the average recovery were 99.31%, 99.21%, 99.04%, 99.59%, (n=6) respectively, and RSDs were 1.86%, 1.24%, 1.37%, 1.15%, respectively.
Conclusion: This method is reliable, repeatable and stable, and has strong specificity. This method can provide a reference for the quality control and standard improvement of Jindan tablets.