Effect of Nd:YAG Laser Irradiation Pretreatment on the Long-Term Bond Strength of Etch-and-Rinse Adhesive to Dentin

PURPOSE

To investigate the effect of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser irradiation pretreatment on the long-term bond strength of an etch-and-rinse adhesive to dentin.

METHODS

Fifty molars were sectioned parallel to the occlusal plane and randomly divided into two groups (n=25 per group): control group (no treatment) and laser group (dentin surfaces were treated with Nd:YAG laser at a setting of 100 mJ/10 Hz). Afterward, resin was bonded to the dentin surface using a two-step etch-and-rinse adhesive (Adper SingleBond 2), and then 150 beams of each group were produced. Each group was divided into three subgroups (n=50 each group): 24 hours of water storage, thermocycling, and NaOCl storage. The microtensile bond strength (MTBS), failure modes, nanoleakage expression, and Masson's trichrome staining were evaluated. An additional 20 molars were sectioned to obtain 2-mm-thick flat dentin slices. These slices were randomly divided into control and laser-treated groups as mentioned previously. Then slices of each group were examined by scanning electron microscopy, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD), and the Knoop hardness test.

RESULTS

The results of ATR-FTIR and Masson's trichrome verified that laser irradiation partly removed collagen fibers from the dentin surface; however, no significant difference was found in the Knoop hardness (p>0.05). The XRD result showed similar crystalline structure regardless of laser pretreatment. There is no significant difference in short-term MTBS between control and laser-treated groups (p>0.05); however, long-term MTBS differed between the groups (p>0.05). Furthermore, the laser-treated group showed less silver deposition than the control group after aging (p<0.05).

CONCLUSION

Pretreatment by Nd:YAG laser irradiation appeared to have a positive effect on the adhesive-dentin bonding in vitro test, and the bonding effectiveness could be preserved after aging.

Stable actively Q-switched single-frequency fiber laser at 1.5 μm based on self-injecting polarization modulation

A new technique for the realization of a stable Q-switched operation in a single-frequency fiber laser based on self-injecting polarization modulation is demonstrated, for the first time to the best of our knowledge. A piezoelectric fiber stretcher was utilized to introduce periodic stress-induced polarization changes. Then the modulation of polarization state transformed into Q switching by virtue of a designed distributed Bragg reflector (DBR) resonant cavity with polarizations loss anisotropy. Finally, a stable actively Q-switched single-frequency fiber laser at 1.5 μm with Gaussian-shape pulse output was achieved. We experimentally found that, the repetition frequency (several hundred kHz) coincided with the working frequency of the polarization modulation, and the pulse width (several hundred ns) reduced with the increasing of the modulating frequency, the modulating amplitude, as well as the pump power. This stable Q-switched single-frequency fiber laser is promising for applications in optical time-domain reflectometry, coherent Doppler wind radar, and optical coherent detection. More importantly, this novel Q-switched technology may be applicable to other DBR single-frequency fiber lasers.

GSK2878175, a pan-genotypic non-nucleoside NS5B polymerase inhibitor, in healthy and treatment-naïve chronic hepatitis C subjects

GSK2878175 is a potent, pan-genotypic, non-nucleoside, nonstructural protein 5B palm polymerase inhibitor being developed for the treatment of chronic hepatitis C (CHC). A first-in-human, randomized, placebo-controlled, dose escalation study, evaluated the safety and pharmacokinetics of GSK2878175 administered as single and repeat oral doses (once daily for 14 days) to healthy volunteers. A separate proof-of-concept, placebo-controlled, repeat dose (once daily for 2 days) study evaluated the safety, pharmacokinetics and antiviral activity of GSK2878175 monotherapy in treatment-naïve, noncirrhotic, subjects with hepatitis C virus (HCV) genotype 1 [1a and 1b], 2, or 3. No deaths or SAEs were reported in either study, and treatment was well-tolerated. Across all the HCV genotypes, GSK2878175 monotherapy at doses of 10, 30 or 60 mg once daily for 2 days produced a statistically significant multilog reduction (P<.001) in plasma HCV RNA log₁₀ IU/mL from Baseline to 24, 48 and 72 hours after the first dose of GSK2878175 compared to placebo. The reduction in HCV RNA was sustained for a prolonged period across all of the active treatment groups, consistent with the long apparent half-life of GSK2878175 that was observed (mean t_1/2 range: 60-63 hours in the CHC subjects). In summary, GSK2878175, when administered to healthy subjects and subjects with CHC, did not reveal any safety concerns that would limit or preclude further clinical development. GSK2878175 monotherapy across a wide dose range produced substantial reduction in HCV RNA, irrespective of HCV genotype. The results from these studies support further evaluation of GSK2878175-based regimens.

Interface phenomena in magnetron sputtered Cu2O/ZnO heterostructures

The interface between ZnO and Cu₂O has been predicted to be a good candidate for use in thin film solar cells. However, the high predicted conversion efficiency has yet to be fully realized experimentally. To explore the underlying causes of this we investigate the interface between ZnO and Cu₂O in magnetron sputtered samples. Two different sample geometries were made: In the first set thin layers of ZnO were deposited on Cu₂O (type A), while in the second set the order was reversed (type B). Using x-ray photoelectron spectroscopy (XPS), an intermediate CuO layer was identified regardless of the order in which the Cu₂O and ZnO layers were deposited. The presence of a CuO layer was supported by transmission electron microscopy (TEM) results. Changes in the electron hole screening conditions were observed in CuO near the interface with ZnO, manifested as changes in the relative peak-to-satellite ratio and the degree of asymmetric broadness in the Cu 2p peak. The suppression of the Cu 2p satellite characteristic of CuO may cause the CuO presence to be overlooked and cause errors in determinations of valence band offsets (VBOs). For the type A samples, we compare four different approaches to XPS-based determination of VBO and find that the most reliable results are obtained when the thin CuO layer and the altered screening conditions at the interface were taken into account. The VBOs were found to range between 2.5 eV and 2.8 eV. For the B type samples a reduction of the Cu 2p-LMM Auger parameter was found as compared to bulk Cu₂O, indicative of quantum confinement in the Cu₂O overlayer.

[Effect of a nano hydroxyapatite desensitizing paste application on dentin bond strength of three self-etch adhesive systems]

Objective: To evaluate a nano-hydroxyapatite (nano-HA) desensitizing paste application on the bond strength of three self-etch adhesives. Methods: Three dentin specimens of about 1 mm thick were cut from two teeth. Scanning electron microscope (SEM) was used to evaluate the dentin surfaces without treatment, after citric acid treatment and after nano-HA treatment. Thirty-six intact third molars extracted for surgical reasons were cut to remove the occlusal enamel with isomet, and then were etched with 1% citric acid for 20 s to simulate the sensitive dentin and divided into two groups randomly using a table of random numbers (n=18): the control group (no treatment) and the HA treated group (with nano-HA paste treatment). Each group was divided into three subgroups randomly using a table of random numbers (n=6). Subgroup A, B and C was bonded with G-Bond, Clearfil S(3) Bond and FL-Bond Ⅱ according to the manufacture's instruction separately. At 24 h after bonding procedure, and after water storage for 6 months, microtensile bond strength of the specimens was tested and the failure mode was analyzed. Results: SEM obeservation showed that citric acid could open the dentin tubules to set up the sensitive dentin model, and the nano-HA could occlude the dentin tubules effectively. For subgroup A, bonding strength of specimens treated with nano-HA ([41.14±8.91] MPa) was significantly high than that of the control group ([34.27±6.16] MPa) at 24 h after bonding procedure (P<0.05). However, after 6 month water ageing, the bonding strength of the control group and the HA treated group showed no significant difference (P>0.05). For subgroup B, specimens with nano-HA application showed lower bonding strength ([30.87±6.41] MPa) than that of the control group ([36.73±5.82] MPa) at 24 h after bonding procedure (P<0.05), and after 6 month water ageing, the bond strength of nano-HA application ([25.73±6.99] MPa) was also lower than that of the control group ([32.33±5.08] MPa) (P<0.05). For subgroup C, the bond strength of the control group and the HA treated group have no significant difference either before or after 6 month water ageing (P>0.05). Failure mode analysis showed that more than half of the samples in all groups were adhesive failure. Conclusions: Nano-HA treatment decreased the bond strength of subgroup B, while had no adverse effect on subgroup A and subgroup C.

Application of a strategy based on metabolomics guided promoting blood circulation bioactivity compounds screening of vinegar

Background

Rice vinegar (RV) and white vinegar (WV) as daily flavoring, have also used as accessory in traditional Chinese medicine processing. As we know, the promoting blood circulation efficiency could be enhanced when herbs processed by vinegar. Number of reports focused on health benefits derived by consumption of vinegar. However, few concerned the blood circulation bioactivity.

Methods

In this paper, a metabolomics guided strategy was proposed to elaborate on the chemical constituents’ variation of two kinds of vinegar. GC–MS coupled with multivariate statistical analysis were conducted to analyze the chemical components in RV and WV and discriminate these two kinds of vinegar. The anti-platelet activities in vitro were investigated by whole blood aggregometry platelet test. And the anticoagulant activities were monitored by the whole blood viscosity, plasma viscosity, packed cell volume, prothrombin time, and four coagulation tests (PT, TT, APTT, FIB) in vivo.

Results

Constituents of RV and WV were globally characterized and 33 potential biomarkers were identified. The contents of four potential alkaloid biomarkers increased with aging time prolonged in RV. RV and its alkaloids metabolites exhibited some anti-platelet effects in vitro and anticoagulant activities in vivo. WV failed to exhibit promoting effects.

Conclusions

Alkaloid metabolites were demonstrated to be the principal compounds contributing to discrimination and it increased with aging time prolonged in RV. RV exhibited the blood circulation bioactivity. The alkaloids of RV contributed to the blood circulation bioactivity.Graphical abstract

[Perioperative management and surgical treatment of neurosurgical critical patients with thrombocytopenia]

OBJECTIVE

To study the perioperative management and surgical treatment of patients with neurosurgical critical diseases and thrombocytopenia.

METHODS

Eleven patients with the diagnosis of neurosurgical critical diseases and thrombocytopenia who received surgical treatment in Department of Neurosurgery, Peking Union Medical College Hospital from 2010 to 2015 were reviewed retrospectively. All eleven patients received platelet transfusions preoperatively. The safety and efficacy of surgical treatment were analyzed by GOS score at 6 months after operations.

RESULTS

Platelet counts of six patients who received minimally invasive surgery reached 80×10(9) /L by platelet transfusions preoperatively. Platelet counts of five patients who received Craniotomy and ventriculoperitoneal shunt reached 100×10(9) /L by platelet transfusions preoperatively. Eight patients received platelet transfusions postoperatively according to a low platelet count 24 hours after operations. Two patients died after surgery and one died after discharge. All other eight survival patients got well recovery with an average GOS score of 4.5 at six months after operations.

CONCLUSIONS

Patients with neurosurgical critical diseases and thrombocytopenia could receive surgical treatment in collaboration with relative departments.

PTPRO represses ERBB2-driven breast oncogenesis by dephosphorylation and endosomal internalization of ERBB2

The plasma membrane-associated tyrosine phosphatase PTPRO is frequently transcriptionally repressed in cancers and signifies poor prognosis of breast cancer patients. In this study, deletion of Ptpro in MMTV-Erbb2 transgenic mice dramatically shortened the mammary tumor latency and accelerated tumor growth due to loss of Ptpro within the breast cancer cells but not in surrounding tissue as confirmed by hetero-transplantation studies. Both in vitro and in vivo data demonstrated that the phosphatase activity was required for the inactivation of ERBB2 and its downstream signaling. PTPRO regulated the phosphorylation status of ERBB2 at Y1248. Co-immunoprecipitation and proximity ligation assay (Duolink) indicated that PTPRO directly physically interacted with ERBB2. Moreover, PTPRO phosphatase activity shortened the half-life of ERBB2 by increasing endocytotic degradation. PTPRO reexpression by demethylation treatment using 5-azacytidine reduced the proliferation and colony formation potential in ERBB2-positive breast cancer cells. Taken together, PTPRO inhibited ERBB2-driven breast cancer through dephosphorylation leading to dual effects of ERBB2 signaling suppression and endosomal internalization of ERBB2, Therefore, reexpression of PTPRO may be a potential therapy for ERBB2-overexpressing breast cancer.

Abnormal white matter structural connectivity in treatment-naïve young adults with borderline personality disorder

OBJECTIVE

The pathogenesis of borderline personality disorder (BPD) is not well understood. We examined the microstructure of white matter in patients with BPD.

METHOD

Treatment-naïve young adult with BPD (N = 30) and young-adult healthy controls (HCs; N = 31) were subjected diffusion tensor imaging (DTI). Microstructural parameters were analyzed via tract-based spatial statistics (TBSS) and post hoc tractography.

RESULTS

TBSS analysis revealed that, relative to the HC group, the BPD group had significantly lower fractional anisotropy (FA) values in the genu and body of the corpus callosum (CC), right superior corona radiate, right anterior corona radiate, as well as higher radial diffusivity (RD) in the left anterior thalamic radiation. Tractography showed that FA values of fiber bundles passing through the fornix were significantly reduced in BPD group relative to HCs. No significant correlations were observed between clinical symptom and DTI indices in BPD group (FDR corrected).

CONCLUSION

Focal microstructural alterations were found in BPD group, mainly in the limbic system and CC. The present findings support the fronto-limbic disconnectivity hypothesis and suggest that abnormal maturation of white matter structures may play an important role in mechanism of BPD.

Comparison of pollutant concentrations from weekly discrete versus composite samples for residential dry-weather runoff

As urbanization has increased, so has degradation of urban streams. Urban water quality monitoring has focused on storm runoff sampling, but in arid climates, dry-weather runoff is a significant contributor of pollutants to aquatic systems. The majority of dry-weather runoff studies sample a small window of the entire dry-season. For this study constituent concentrations were compared using two sampling protocols. The first protocol repeatedly collected samples on the same day of the week at the same time of day. The second protocol collected samples during two week-long intensive sampling events consisting of sample collection every hour for 24 h for seven consecutive days. The two protocols were compared to determine if sampling at the same time of the week was representative of the entire week. For nitrate, total phosphorous, fipronil, permethrin, total organic carbon, and total suspended solids, sampling at the same time was not representative of the weekly mean; however, variability was observed between sites and constituents. For those constituent concentrations with significant differences seen between the two protocols, load adjustment factors (LAF) were determined, using a ratio of treatment means, and employed to adjust dry-season load estimates. Future work should include determining if LAF values can be used at similar sites excluded from the study or for similar constituents from the current sampling sites.

[Effects of exogenous enzymes on the degradation of adhesive-dentin interfaces]

OBJECTIVE

To compare the effects of exogenous enzymes on the degradation of adhesive-dentin interface.

METHODS

Forty molars were sectioned to expose the middle-coronal dentin surface and randomly divided into two adhesive systems: an etch-and-rinse adhesive Adper Single Bond 2 and a self-etching adhesive G-Bond. After composite building up, the specimens were then randomly assigned to four groups(n=5 for each group)as follows: group 1, 24 h of water storage(the control group); group 2, six months of water storage; group 3, twelve weeks storage in artificial saliva containing clostridium histolyticum collagenase; group 4, twelve weeks storage in artificial saliva containing cholesterolesterase. The microtensile bond strengths(MTBS)were then tested. The failure modes and nanoleakage were analyzed.

RESULTS

After aging treatments, the three aging groups showed significantly lower MTBS compared with the control group in both adhesive systems(P<0.05). For etch-and-rinse adhesive Adper Single Bond 2, the MTBS of group 3([19.6±3.5]MPa)was lower than that of group 2([23.4±4.2]MPa)and group 4([24.2±4.2]MPa)(P<0.05). For self-etching adhesive G-Bond, there was no difference on MTBS among different aging groups(P>0.05). SEM observation showed that, compared with the control group, water storage(group 2)and the exogenous enzymes(group 3 and 4)increased the nanoleakage expression(silver deposition)of both adhesive systems. Adhesive failure was the predominant fracture modes in all groups.

CONCLUSIONS

Storage in artificial saliva containing clostridium histolyticum collagenase or cholesterol esterase could be used to accelerate the degradation process of adhesive-dentine interface.

Integration of Physiologically-Based Pharmacokinetic Modeling into Early Clinical Development: An Investigation of the Pharmacokinetic Nonlinearity

BMS-911543, a promising anticancer agent, exhibited time-dependent and dose-dependent nonlinear pharmacokinetics (PKs) in its first-in-human (FIH) study. Initial physiologically based pharmacokinetic (PBPK) modeling efforts using CYP1A2-mediated clearance kinetics were unsuccessful; however, further model analysis revealed that CYP1A2 time-dependent inhibition (TDI) and perhaps other factors could be keys to the nonlinearity. Subsequent experiments in human liver microsomes showed that the compound was a time-dependent inhibitor of CYP1A2 and were used to determine the enzyme inactivation parameter values. In addition, a rat tissue distribution study was conducted and human plasma samples were profiled to support the refinement of the PBPK model. It was concluded that the interplay between four BMS-911543 properties, namely, low solubility, saturation of the metabolizing enzyme CYP1A2, CYP1A2 TDI, and CYP1A2 induction likely resulted in the time-dependent and dose-dependent nonlinear PKs. The methodology of PBPK model-guided unmasking of compound properties can serve as a general practice for mechanistic understanding of a new compound's disposition.

Health and production traits in bovine are associated with single nucleotide polymorphisms in the NOD2 gene

The NOD2 gene plays a fundamental role in initiating the inflammatory and subsequent immune response. NOD2 was previously identified as a susceptibility locus for inflammatory bowel diseases in humans. In this study, we detected 2 mutations in exon 12 (A→T, G→A) among 5 cattle breeds (N = 315) and analyzed their associations with production traits and genetic resistance against bovine mastitis in Chinese Holstein and Chinese Simmental breeds (N = 218). The transitions (A→T) at position 114 bp were associated with somatic cell score (P < 0.01). The G→A at position 1594 bp plays a critical role in increasing 305-day milk yields. In Chinese Holstein and Chinese Simmental breeds, the BB genotype may contribute to disease susceptibility. Compared to all genotypic combinations, the A, B, and FF genotypes are beneficial not only for reducing somatic cell score but also for increasing production.

Long-Term Outcomes After Small-Bone-Window Posterior Fossa Decompression and Duraplasty in Adults with Chiari Malformation Type I

BACKGROUND

Small-bone-window posterior fossa decompression with duraplasty is one of the popular surgical options for Chiari malformation type I, but its efficacy is controversial and the risk factors of clinical outcome remain unclear.

METHODS

The study cohort included 152 patients with Chiari malformation type I who received small-bone-window posterior fossa decompression at Beijing Tiantan hospital from January 2008 to September 2009. All patients underwent combined surgical procedures: a small-bone-window suboccipital decompression (diameter, 2.5-3 cm) and a C1 laminectomy (1.5- to 2-cm wide) followed by a duraplasty with an autologous graft. Clinical manifestations, radiologic features, and follow-up data during a 6-year span were analyzed. Risk factors associated with outcome were investigated by the use of χ(2) analysis and logistic regression analysis.

RESULTS

The average follow-up duration was 74 months. Symptoms were improved in 126 patients (82.9%), remained stable in 21 patients (13.8%), and deteriorated in 5 patients (3.3%). There was no mortality. Postoperative magnetic resonance imaging scans were available for all patients. Preoperatively, 112 patients were associated with syringomyelia, and the follow-up magnetic resonance images showed obvious reduction of syringomyelia in 73 patients (65.2%) and no significant change in 39 patients (34.8%). In addition, enlargement of the cistern magna was observed in 92 patients (85.2%). Regression analysis indicates preoperative motor dysfunction, brainstem herniation and basilar invagination may influence the clinical outcome (P < 0.05).

CONCLUSIONS

Small-bone-window posterior fossa decompression with duraplasty is an effective and safe treatment option with a low complication rate. Motor dysfunction, brainstem herniation, and basilar invagination are predictors of poor clinical prognosis.