D-amino acids were believed to have no function in higher organisms several years ago. Recently, D-serine was proved to be synthesized by astrocytes in vivo and be released to work as an effective coagonist at the “glycine-binding” site of the N-methyl-D-aspartate (NMDA) glutamate receptors in central nervous system. In this paper, the synthesis, metabolism and function of D-serine were reviewed briefly.

Objective To study the effects of CBL teaching mode on treatment plan making process among orthodontic postgraduates. Methods Totally 42 junior and senior orthodontic post-graduates were randomly divided into 2 groups (21 per group)named as experimental group and test group. Each group was further divided in to 3 teams involved in CBL and traditional teaching. Six cases of the same type malocclusion were selected each time;after 4 teaching cycle,test scores of two groups were analyzed with SPSS 19.0. Results were shown as mean ± standard deviation and t test andχ2 test were applied to evaluate the rationality and accuracy of treatment plan made by students. Survey questionnaire were issued to teachers and students after class and the assessment results of CBL teaching mode were summed up. Results Test scores were (88.61±8.34)in experimental group and (76.13±8.59)in control group with significant differences (t=3.16,P=0.01). Pass rate of two groups were 96.12%and 87.51%with significant differences (χ2=4.76,P=0.02). During the first teaching program, accurate rates of experimental group and control group were respectively 31.00% and 36.70% and ra-tionality were 33.31%and 33.30%. During the second teaching program,accurate rates of experimen-tal group and control group were 68.80%and 45.70%and rationality were 62.72%and 43.37%. During the third teaching program,accurate rates of experimental group and control group were 89.70% and 51.20%,and rationality were 95.00% and 66.70%. During the fourth program,accurate rates of ex-perimental group and control group were respectively 97.80% and 55.30% and rationality were 98.30% and 75.60%. Conclusions CBL teaching mode is helpful to improve the students' ability of analyzing clinical cases and making more accurate and rational treatment plan,however the increasing teaching cost and the course load are also involved.

Objective To explore the applied value of thyroid imaging reporting and data system (TI-RADS) strati?fication in diagnosing thyroid nodules in patients with different ages.Methods A total of 527 patients with thyroid nod?ules (aged 26-65) were divided into four groups:aged 26-35 group, aged 36-45 group, aged 46-55 group and aged 56-65 group. TI-RADS was used to evaluate patients in four groups. The results of TI-RADS were compared with the pathologic di?agnostic analysis. Results For the low aged groups (aged 26-35 group and aged 36-45 group), the positive predictive val?ue, the negative predictive value and accuracy rate were more than 90%. With regard to the patients aged 46-55, the positive and negative predictive values and accuracy rate were 81.5%, 87.5%, and 81.9%, respectively. The positive and negative predictive values, accuracy rate were 76.6%,88.8%and 77.9%for patients aged 56-65 group. The diagnostic rate of TI-RADS in patients with thyroid lesions was lower in aged 56-65 group than that of other groups. Conclusion TI-RADS method is affected by age. The diagnostic rate is lower in the high age group than that of the low age group.

Objective To establish the method of contact heat evoked potential(CHEP)and to explore the value of this evoked potential in pain testing of patients with cerebral infarction.Methods A total of 100 healthy volunteers and 30 patients were examined.The healthy volunteers were divided into 3 groups according to the length of their arms:(Group A:56.0～65.0 cm ;Group B :65.5～74.0 cm ;Group C :74.5～83.0 cm).A recently de- veloped heat-foil technique with a rapid temperature rising rate at 70℃/s was used to elicit pain and contact heat e- voked potentials.Contact heat was delivered via one circular thermode(diameter 27 mm,area 573 mm~2)and set at two intensity levels(49.5℃and 54.5℃)to three body sites:the thenar eminence,the dorsum of hand and proximal volar forearm.The subjects were asked to rate the pain with numerical rating scale after each stimulus and CHEP was recorded from Cz and Pz.The association between stimulus intensities and pain rating was explored,the main compo- nents of the evuked potential were watched.CHEP,sensory conduction velocity(SCV)and somatosensory evoked potentials(SEP)were performed in patients with hemi-anesthesia caused by cerebral infarction.Results The pain intensity ratings were 3.2?0.3 and 4.4?0.5 at thenar eminence,5.0?0.7 and 6.3?0.8 at the dorsum of hand and 5.3?0.6 and 7.2?0.5 at the proximal volar forearm when the temperature of 49.5℃and 54.5℃was applied, respectively;Three components,Cz/N550,Cz/P750 and Pz/P1000,were identified in the evoked potentials.Cz/ N550 and Cz/P750 appeared when the dorsum of hand and proximal volar forearm were stimulated.In contrast,Pz/ P1000 could be identified when nociceptors of thenar eminence and proximal volar fbrearm were excited.In the pa- tients with cerebral infarction,CHEP disappeared or became abnormal on one side,while SCV and SEP were normal on that side.Conclusion It was suggested that CHEP could be elicited reliably in the controls.CHEP is helpful in the assessment of analgesia in patients with cerebral infarction.

Objective To evoke cerebral potentials by stimulating nociceptive fibers with contact heat evoked potentials stimulator (CHEPS)and estimate the nerve conduction velocities of peripheral nerve fibers mediating these responses.Methods Subjects were set in supine position.A heat-foil technology with a rapid rising speed at 70 ℃/s was used to elicit pain and contact heat evoked potentials(CHEP).Contact heat was delivered via one circular thermode (diameter 27 mm,area 573 mm~2).Thermal stimuli were sent at two intensity levels (49.5 ℃ and 54.5 ℃) to three body sites:thenar eminence,the dorsum of hand and proximal volar forarm.Contact heat evoked potentials were recorded from Cz and Pz.A systemic effect between stimulus intensities and pain rating were observed,the main components of this evoked potential were observed.Nerve conduction velocity was calculated from latency difference of CHEP and center to center distance of distal and proximal stimulus arrays.Results The pain intensity rating was 3.2?0.3 and 4.4?0.5 when thenar eminence was stimulated at the temperature of 49.5 ℃ and 54.5 ℃ respectively;the rating was 6.3?0.8 and 7.2?0.5 when the dorsum of hand and proximal volar forarm were stimulated at the temperature of 54.5 ℃ respectively.Three components,Cz/N550,Cz/P750 and Pz/P1000,were found in the evoked potentials.Nerve conduction velocities of the fibers were (12.9?7.5) and (1.7?0.4) m/s respectively,which were corresponding to those of A8 fiber and C fiber.Conclusions CHEPs can be elicited reliably and stably.Velocities of peripheral nerve fibers demonstrate that A8 fiber and C fiber mediate the response.

Blood Gas Analysis ; Continuous Positive Airway Pressure ; instrumentation ; Humans ; Infant ; Infant, Newborn ; Pneumonia ; blood ; physiopathology ; therapy ; Respiration

Cardiovascular Diseases ; Humans ; Induced Pluripotent Stem Cells

Objective To investigate the effect of RO20-1724 on the cognitive function in immature rats after ketamine anesthesia.Methods Ninety-six SD rats of both sexes,aged 21 days,weighing 45-55 kg,were randomly divided into 8 groups ( n =12 each):control group (group C) ; ketamine group (group K) ; ketamine + normal saline group (group K + N) ; ketamine + anhydrous alcohol group (group K + A) ; ketamine + 4 different doses of RO20-1724 groups (group K + R1-4 ).The rats were anesthetized with intraperitoneal injection of kctamine 70 mg/kg in groups K,K+N,K+A and K+.R1-4.Normal saline 2 ml,anhydrous alcohol (in normal saline 2 ml),and RO20-1724 0.25,0.50,0.75 and 1.00 mg/kg (in anhydrous alcohol 8 μl and then in normal saline 2 ml) were injected intraperitoneally in groups K + N,K + A and K + R1-4 respectively 30 min later.Six rats from each group were randomly selected at 24 h after administration and Morris water maze was used to test the ability of learning and memory.Six rats from each group were sacrificed at 48 h after administration and hippocampus and cerebral cortex were removed for determination of the expression of CREB and phospho-CREB (p-CREB) by Western blot.Ressults Compared with group C,the escape latency was significantly prolonged at 2-4 days after administration,the number of animals' swimming across the platform decreased,and the expression of CREB and pCREB in hippocampus and cerebral cortex down-regulated in groups K,K+ N,K+ E,K+ R1 and K+ R2(P ＜0.05 ).Compared with group K,the escape latency was significantly shortened at 2-4 days after administration,the number of animals' swimming across the platform increased,and the expression of CREB and p-CREB in hippocampus and cerebral cortex up-regulated in groups K + R3 and K + R4 ( P ＜ 0.05).Compared with groups K + R1 and K + R2,the escape latency was significantly shortened at 2-4 days after administration,the number of animals' swimming across the platform increased,and the expression of CREB and p-CREB in hippocampus and cerebral cortex up-regulated in groups K+ R3 and K+ P4(P ＜ 0.05).There were no significant differences in the escape latency,the number of animals' swimming across the platform,and the expression of CREB and p-CREB in hippocampus and cerebral cortex between groups K + R1 and K + R2,and between groups K + R3 and K + R4 ( P ＞ 0.05 ).Conclusion RO20-1724 0.75-1.00 mg/kg can improve ketamine-induced cognitive dysfunction by up-regulating CREB and p-CREB expression in hippocampus and cerebral cortex in immature rats.

Objective To compare the difference of therapeutic effect of surgical operation and non-operation for acute damnification of elbow ulnar collateral ligament in rabbits.Methods A total of 81 New Zealand rabbits were randomly and equally divided into three groups(27 rabbits per group),ie,Group A(control group):the ulnar collateral ligaments of right elbow joint were only enclosed;Group B:the ulnar collateral ligaments of right elbow joint were severed and sutured;Group C:the ulnar collateral ligaments of right elbow joint were severed,without suture.The biomechanics was detected at time intervals of 3 and 6 weeks.Results Twelve weeks after transplantation,the displacements of the ligaments in Groups B and C were(6.06±0.4)mm and(7.72±0.44)mm,with statistical difference(P ＜ 0.05).The displacement of the ligaments in Group A was(5.87±0.46)mm,which was similar to that of Group B(P＞0.05).The maximum loads of the ligaments of Groups B and C were(68.23±5.64)N and (42.45±3.66)N respectively,with statistical difference(P＜0.05).The maximum load of the ligaments of Group A was(72.86±2.99)N,which was similar to that of Group B(P ＞ 0.05).The rigidities of the ligaments of Groups B and C were(11.33±1.52)N/mm and(5.52±0.67)N/mm respectively,with significant difference(P ＜ 0.05).The rigidities of the ligaments of Group A was(12.49±1.44)N/mm,which was similar to that of Group B(P ＞ 0.05).The power consumption of the ligaments of Groups B and C were(0.206±0.017)J and(0.163±0.013)J respectively,with statistical difference(P＜0.05).The power consumption of the ligaments of Group A was(0.213±0.010)J,which was similar to that of Group B(P＞0.05).Conclusion Surgical operation is more effective than the non-operation in dealing with acute damnification of the ulnar collateral ligaments of elbow ulnar collateral ligament in rabbits.

BACKGROUND:Compared with smooth titanium, titania nanotubes cannot only induce mesenchymal stem cels osteogenic differentiation and promote bone integration, but also be used as drug nanocarriers. OBJECTIVE:To prepare dexamethasone-loaded titania nanotube system and to test its drug release characteristics. METHODS:Titania nanotubes were prepared by electrochemical anodic oxidation, and dexamethasone was dripped onto the prepared titania nanotubes. Subsequently layer by layer self-assembly technology was employed to fabricate gelatin/chitosan multilayered structure on the prepared samples. Scanning electron microscope and contact angle test were carried out during the process of building the gelatin/chitosan multilayered structure. The drug release was measured by a ultraviolet spectrophotometer. RESULTS AND CONCLUSION:Under the scanning electron microscopy, the fabricated titania nanotubes had integral structure with even tube size of about 70 nm and arranged regularly, and the nanotubes were completely covered and sealed by the gelatin/chitosan multilayered membrane. Contact angle test results showed that ever since the fifth layer, contact angles changed alternately and displayed a zigzag profile. Ultraviolet spectrophotometer test results showed that when cultured for 3 hours, the cumulative drug release was about 32.7% and demonstrated an initial burst folowed by sustained release. When cultured for 24 hours, the cumulative drug release about 52.3%. However, after cultured for 7 days, little drug release was detected. And there was about 8.0%-10.0% dexamethasone of initial loading preserved in nanotubes.