An economic and facilely prepared dopamine ( DA) sensor have been successfully fabricated by the electrodeposition of copper on single-walled carbon nanotubes ( SWNTs )/Nafion-modified glassy carbon electrode. The morphology of the material was observed by scanning electron microscopy ( SEM) and element composition of the material was investigated by energy dispersive X-ray spectroscopy ( EDX ) . Tests with various scan rates and pH conditions indicated that an adsorption-controlled process occured in the electrochemical system. The mechanism of the electrode reaction of dopamine involved a two-electron process which was accompanied by a deprotonation step. Electrochemical parameters were calculated with the electron transfer number as 2 . 67 , the charge transfer coefficients as 0 . 6 , the apparent heterogeneous electron transfer rate constant as 1. 38 s-1 . Under the optimal conditions with differential pulse voltammetric measurement, the linear equation was Ipa(μA)=-0. 054c (μmol/L)-3. 82(R2=0. 9988), with linear range of 5-100 μmol/L and detection limit of 0 . 0135 μmol/L ( S/N=3 ) . The main advantages of sensor included facile fabrication approach, high sensitivity, good stability and high reproducibility. The sensor was applied to the detection of DA in volunteer urine by differential pulse voltammetry with favorable recoveries of 96 . 5%-100 . 4% and relative standard deviations (RSDs) of 1. 2%-2. 4%.

Objective To study the risk factors of periventricular-intraventricular hemorrhage (PIVH) in extremely low birth weight infants(ELBWI). Methods A retrospective study was performed in 41 ELBWI hospitalized between January 2001 and August 2008. Univariate analysis and Logistic regression analysis were performed to detect the risk factors of PIVH. Results Of 41ELBWI, twenty-three suffered from PIVH with the incidence of 56.1%. Univariate analysis revealed that,in PIVH group,gestational age,mean blood pressure and the minimum values of blood pressure were lower than non-PIVH group[ ( 27.1 ± 1.9 ) weeks vs ( 28. 7 ± 1.6) weeks, t = 2. 834, P ＜ 0. 05 ;(28.9±4.8) mm Hg vs (33.1±4.9) mm Hg, t=-2.747,P＜0. 05; (24.4±4.3) mm Hg vs (31.4 ± 6.6) mm Hg,t= -3. 863, P＜0. 05], while blood pressure fluctuation and the highest values of PaCO2 during the first week of life were higher[(19.0 ± 5.2) mm Hg vs (13.7 ± 4. 8) mm Hg;(60. 2± 19. 4) mm Hg vs (49.5±12.1) mm Hg] (t= 3. 310 and 2. 166, P＜0. 05), the incidence of administration of pulmonary surfactant, neonatal respiratory distress syndrome, shock, hypotension before 4 days of age, hyperglycemia and mechanical ventilation therapy were higher[73. 9 % (17/23) vs 27. 8%(5/18), 60. 9%(14/23) vs 27.8%(5/18),52. 2%(12/23) vs 5.5%(1/18),73. 9%(17/23) vs 33.3%(6/18) ,78. 3%(18/23) vs 44. 5%(8/18),87. 0% (20/23) vs 44. 5% (8/18)]( all P＜0.05).Multivariate Logistic analysis revealed that blood pressure fluctuation (OR = 1. 260, 95% CI: 1. 009-1. 572, P = 0. 041 ) and lowest mean blood pressure(OR = 0. 805,95 % CI: 0. 672-0. 965, P = 0. 019)were risk factors of PIVH. Among twenty-eight ELBWI received mechanical ventilation, only peakinspiratory pressure(OR=- 2. 086,95% CI: 1. 140-3. 819, P= 0. 017) was the risk factor of PIVH by Logistic analysis. Conclusions Low blood pressure and blood pressure fluctuation may be risk factors of PIVH in ELBWI. The high values of peak inspiratory pressure is a risk factor of ELBWI with mechanical ventilation.

Objective To investigate the short-term clinical outcomes and perinatal risk factors in very low birth weight infants (VLBWI) with delayed enteral feeding (DEF).Methods Three hundred and fifty-five cases of VLBWI admitted to neonatal intensive care unit from Jan 2007 to Oct 2011 served as study objects,and the clinical data of which were analysed retrospectively.According to days to initiate enteral feeding after birth,355 VLBWI were divided into two groups:DEF group (initiate enteral feeds ≥5 days,n =55)and early feeding group (initiate enteral feeds ≤4 days,n =298).The short-term clinical outcomes were compared in 299 cases,including DEF group 44 cases and early feeding group 255 cases,in which cure or improvement were achieved and hospital stay ＞ 14 d.The perinatal risk factors were subjected to univariate and multivariate logistic regression analysis.Results The incidence of DEF was 16.05％ (57/355) in VLBWI.The time to regain birth weight in DEF group was significantly longer than early feeding group [(11.86 ± 3.86) d vs (9.76 ± 3.83) d,P ＜ 0.01],and the incidences of parenteral nutrition associated cholestasis [27.27％ (12/44)] and extrauterine growth retardation at discharge [79.55 ％ (35/44)] in DEF group were also significantly higher than early feeding group respectively [11.76％ (30/255) and 61.57％ (157/255),P ＜ 0.05].Multivariable logistic regression analysis showed that infants born to mother with placental abruption had higher risk of exposure for DEF than those without placental abruption (OR =2.74,95％ CI 1.06 ～7.05,P ＜ 0.05).Similarly,infants with mechanical ventilation had also higher odds of DEF than those with-out mechanical ventilation (OR =3.51,95 ％ CI 1.92 ～ 6.42,P ＜ 0.01).Conclusion Placental abruption and mechanical ventilation are independent risk factors for DEF in VLBWI.Improving neonatal outcome through enhancing obstetric quality and strengthening cooperation between obstetric and neonatology department is still the key to reduce DEF in VLBWI.

Objectives To investigate the clinical characteristics and prognosis of late-onset group B streptococcal (GBS) sepsis. Methods From Jan. 2007 to Dec. 2011, iffteen neonates diagnosed with late onset GBS sepsis at discharge from NICU were retrospectively analyzed, meanwhile, thirty-four neonates diagnosed with late onset non-GBS Gram-positive bacteria sepsis at discharge were selected as controls during the same period. Results There were signiifcant differences in occurrence rates of shortness of breath, convulsion and apnea between late onset non-GBS sepsis group and late onset GBS sepsis group (P<0.05). The percentages of neonates with white blood cell count (CSF)>100×106/L, high-sensitivity C-reaction protein (hsCRP)>100 mg/L and glucose in CSF<3.11 mmol/L in late onset GBS sepsis group were higher than those in late onset non-GBS sepsis group (P<0.05). GBS was sensitive to penicillin, ampicillin, ceftriaxone, piperacillin/tazobactam, levolfoxacin and vancomycin. The rates of GBS resistance to erythromycin and gentamycin were both 87.5%. There were signiifcant differences in occurrence rates of meningitis, hydrocephalus and ependymitis between late onset GBS sepsis group and late onset non-GBS sepsis group (P<0.05), while no difference in mortality was found between two groups (P>0.05). Conclusions The late onset GBS sepsis is in-sidious, atypical, with many complications and sequelae. It is important for the suspicious neonates to use effective antibiotics as early as possible.

Objective To evaluate nutritional status during hospitalization of very low birth weight infant (VLBWI) and to analyze the risk factors for extrauterine growth retardation (EUGR) at discharge.Methods VLBWIs in neonatal intensive care unit (NICU),＜12 hours after birth on admission and length of hospital stay over 14 days from January 10,2007 to October 1,2011,were retrospectively studied.Relevant information,including perinatal data,weekly nutrition supplements and weight gain,and neonatal complications were collected.Data were analyzed by Chi-square test,t-test and multivariate Logistic regression analysis.Results In all 256 VLBWIs recruited,61 (23.8％) were small for gestational age at birth.One hundred and seventy-two cases,who were EUGR by weight at discharge,were divided into EUGR group.While the other 84cases were divided into non-EUGR group.The mean gestational age and mean birth weight of EUGR infants were (29.3± 1.2) weeks and (1 240± 170) g,among them,53.5％ (92/172) were extreme EUGR.Univariate analysis showed that the total energy intake [(84.9±20.9) kcal/(kg · d)],protein intake [(2.6±0.5) g/(kg · d)] and proportion ofenteral nutrition [(26.1 ± 15.3) ％] on day 7 of EUGR infants were lower than those ofnon-EUGR ones [(92.4±20.2) kcal/(kg · d),(2.8±0.5) g/(kg · d) and (30.2± 13.2) ％,respectively,t=-2.71,P=0.007; t=-2.19,P=0.030; t=-2.10,P=0.037].The enteral nutrition at the time to regain birth weight in EUGR group was lower than those in non-EUGR group [(36.4±21.6) kcal/(kg · d)vs (44.2±24.1) kcal/(kg · d),t=-2.58,P=0.011],the average growth rate after regaining birth weight and enteral nutrition proportion on day 14 were lower [(15.5±4.1) g/(kg · d) vs (17.3±3.3) g/(kg · d),(44.6± 16.6) ％ vs (49.5± 14.4) ％,respectively; t=-3.61,P=0.000; t=-2.42,P=0.016].The duration of parenteral nutrition in EUGR infants was longer than that in the non-EUGR infants [(39.6± 13.8) d vs (34.1 ±8.6) d,t=3.94,P=0.000].Multivariable logistic regression showed that small for gestational age at birth,low protein intake and low enteral nutrition proportion on day 7,low rate of weight gain after regaining birth weight were associated with EUGR on discharge,and small for gestational age at birth was the leading risk factor (OR=42.66,95％CI:9.09-200.23).Conclusions The incidence of EUGR among VLBWIs is high on discharge.Enhancing perinatal health care and early rational nutrition support are critical to reduce the incidence of EUGR and improve the neuro-developmental prognosis of these babies.

Objective To compare the clinical application of FACS analysis indicators and traditional infection indicators in early diagnosis of infection in premature infants .Methods 60 premature infants were divided into the infected group (n=29) and non-in-fected group(n=31) according to their clinical symptoms and laboratory results .BD FACSCanto Flow Cytometry was employed to detect CD11b ,CD64 and CD45RO ,BACTEC 9120 Automated Blood Culture System was used to conduct body fluids and secretions culture .Sysmex XE-5000 Automated Hematology Analyzers and i-CHROMA Reader Immunofluorescence Analyzer were adopted to conduct the complete blood count test and hypersensitive C-reactive protein (hs-CRP) detection ,respectively .Receiver operator characteristic(ROC) curve was used to analyze the diagnostic value of indexes above in preterm infants with infection ,and their sen-sitivity ,specificity ,positive predictive value and negative predictive value were calculated .Results On the first day after birth ,neu-trophil CD11b ,CD64 ,monocyte CD64 and hs-CRP levels of preterm infants in infection group were obviously higher than those in non-infection group(P<0 .05) .Differences of CD45RO ,WBC ,neutrophil absolute and percentage between the two groups showed no statistical significance(P>0 .05) .ROC area under the curve(AUC)>0 .7 was found in Neutrophil CD64 ,monocyte CD64 and hs-CRP ,which had higher value in early diagnosis of infection in premature infants .The highest sensitivity ,specificity ,positive pre-dictive value and negative predictive value were 79 .31% ,96 .78% ,83 .34% and 75 .00% ,respectively .Conclusion FACS analysis indicators has better clinical value in the early diagnosis of infection in premature infants .

The utilization of optimal orthodontic force is crucial to prevent undesirable side effects and ensure efficient tooth movement during orthodontic treatment.However,the sensitivity of existing detection techniques is not sufficient,and the criteria for evaluating optimal force have not been yet established.Here,by employing 3D finite element analysis methodology,we found that the apical distal region(A-D region)of mesial roots is particularly sensitive to orthodontic force in rats.Tartrate-resistant acidic phosphatase(TRAP)-positive osteoclasts began accumulating in the A-D region under the force of 40 grams(g),leading to alveolar bone resorption and tooth movement.When the force reached 80 g,TRAP-positive osteoclasts started appearing on the root surface in the A-D region.Additionally,micro-computed tomography revealed a significant root resorption at 80 g.Notably,the A-D region was identified as a major contributor to whole root resorption.It was determined that 40 g is the minimum effective force for tooth movement with minimal side effects according to the analysis of tooth movement,inclination,and hyalinization.These findings suggest that the A-D region with its changes on the root surface is an important consideration and sensitive indicator when evaluating orthodontic forces for a rat model.Collectively,our investigations into this region would aid in offering valuable implications for preventing and minimizing root resorption during patients'orthodontic treatment.

Bone regeneration remains a great clinical challenge. Low intensity near-infrared (NIR) light showed strong potential to promote tissue regeneration, offering a promising strategy for bone defect regeneration. However, the effect and underlying mechanism of NIR on bone regeneration remain unclear. We demonstrated that bone regeneration in the rat skull defect model was significantly accelerated with low-intensity NIR stimulation. In vitro studies showed that NIR stimulation could promote the osteoblast differentiation in bone mesenchymal stem cells (BMSCs) and MC3T3-E1 cells, which was associated with increased ubiquitination of the core circadian clock protein Cryptochrome 1 (CRY1) in the nucleus. We found that the reduction of CRY1 induced by NIR light activated the bone morphogenetic protein (BMP) signaling pathways, promoting SMAD1/5/9 phosphorylation and increasing the expression levels of Runx2 and Osterix. NIR light treatment may act through sodium voltage-gated channel Scn4a, which may be a potential responder of NIR light to accelerate bone regeneration. Together, these findings suggest that low-intensity NIR light may promote in situ bone regeneration in a CRY1-dependent manner, providing a novel, efficient and non-invasive strategy to promote bone regeneration for clinical bone defects.
Animals ; Rats ; Bone Morphogenetic Protein 2/metabolism* ; Bone Regeneration ; Cell Differentiation ; Circadian Clocks ; Cryptochromes/metabolism* ; Osteoblasts/metabolism* ; Osteogenesis ; Transcription Factors/metabolism*