Novel hexameric tin carboxylate clusters as efficient negative-tone EUV photoresists: high resolution with well-defined patterns under low energy doses.

Synthesis of two novel tin carboxylate clusters (RSn)6(R'CO2)8O4Cl2 is described, and their structures have been characterized by X-ray diffraction. These clusters have irregular ladder geometry to form very smooth films with small surface roughness (RMS <0.7 nm) over a large domain. EUV lithography can be used to resolve half pitches (HPs) in the order of 15-16 nm with line width roughness (LWR = 4.5-6.0 nm) using small doses (20-90 mJ cm-2). Cluster 1 (R = n-butyl; R'CO2 = 2-methyl-3-butenoate) contains only a radical precursor and cluster 2 (R = vinyl, R'CO2 = 2-methylbutyrate) bears both a radical precursor and an acceptor; the latter is much better than the former in EUV and e-beam photosensitivity. For these clusters, the mechanisms of EUV irradiation have been elucidated with high resolution X-ray photoelectron spectroscopy (HRXPS) and reflective Fourier-transform infrared spectroscopy (FTIR). At low EUV doses, two clusters undergo a Sn-Cl bond cleavage together with a typical decarboxylation to generate carbon radicals. The n-butyl groups of cluster 1 are prone to cleavage whereas the vinyl-Sn bonds of species 2 are inert toward EUV irradiation; participation of radical polymerization is evident for the latter.

Electrophysiological evidence for the characteristics of implicit self-schema and other-schema in patients with major depressive disorder: An event-related potential study.

Background: The significance of implicit self-schema and other-schema in major depressive disorder (MDD) is highlighted by both cognitive theory and attachment theory. The purpose of the current study was to investigate the behavioral and event-related potential (ERP) characteristics of implicit schemas in MDD patients. Methods: The current study recruited 40 patients with MDD and 33 healthy controls (HCs). The participants were screened for mental disorders using the Mini-International Neuropsychiatric Interview. Hamilton Depression Rating Scale-17 and Hamilton Anxiety Rating Scale-14 were employed to assess the clinical symptoms. Extrinsic Affective Simon Task (EAST) was conducted to measure the characteristics of implicit schemas. Meanwhile, reaction time and electroencephalogram data were recorded. Results: Behavioral indexes showed that HCs responded faster to positive self and positive others than negative self (t = -3.304, p = 0.002, Cohen's d = 0.575) and negative others (t = -3.155, p = 0.003, Cohen's d = 0.549), respectively. However, MDD did not show this pattern (p > 0.05). The difference in other-EAST effect between HCs and MDD was significant (t = 2.937, p = 0.004, Cohen's d = 0.691). The ERP indicators of self-schema showed that under the condition of positive self, the mean amplitude of LPP in MDD was significantly smaller than that in HCs (t = -2.180, p = 0.034, Cohen's d = 0.902). The ERP indexes of other-schema showed that HCs had a larger absolute value of N200 peak amplitude for negative others (t = 2.950, p = 0.005, Cohen's d = 0.584) and a larger P300 peak amplitude for positive others (t = 2.185, p = 0.033, Cohen's d = 0.433). The above patterns were not shown in MDD (p > 0.05). The comparison between groups found that under the condition of negative others, the absolute value of N200 peak amplitude in HCs was larger than that in MDD (t = 2.833, p = 0.006, Cohen's d = 1.404); under the condition of positive others, the P300 peak amplitude (t = -2.906, p = 0.005, Cohen's d = 1.602) and LPP amplitude (t = -2.367, p = 0.022, Cohen's d = 1.100) in MDD were smaller than that in HCs. Conclusion: Patients with MDD lack positive self-schema and positive other-schema. Implicit other-schema might be related to abnormalities in both the early automatic processing stage and the late elaborate processing stage, while the implicit self-schema might be related only to the abnormality in the late elaborate processing stage.

Foraging behavior and pollination of carpenter bees Xylocopa spp. (Hymenoptera: Apidae).

Large carpenter bees (the genus Xylocopa), as an important group of bees (Apidae), are common visitors to flowering plants in tropics and subtropics. Their foraging behavior is characterized by long season of activity, high diversity of foraging plants, tolerance of high temperatures, activity under low illumination levels, and buzz pollination. These traits make them to be attractive pollinators for agricultural pollination in hot climates, especially in greenhouses, night-blooming plants, and some Solanum. In recent years, large carpenter bees have been demonstrated have efficient pollination service in blueberries, passion flower, runner bean, greenhouse tomatoes and greenhouse melons in foreign countries. However, evidence for their importance and effectiveness as crop pollinators is lacking for most plant species in China. This article reviewed the research progress on foraging behavior and pollination of Xylocopa, with the aim to provide a theoretical basis for the conservation management and utilization of large carpenter bees.

Enhanced biocompatibility and osteogenic potential of mesoporous magnesium silicate/polycaprolactone/wheat protein composite scaffolds.

BACKGROUND: Successful bone tissue engineering using scaffolds is primarily dependent on the properties of the scaffold, including biocompatibility, highly interconnected porosity, and mechanical integrity. METHODS: In this study, we propose new composite scaffolds consisting of mesoporous magnesium silicate (m_MS), polycaprolactone (PCL), and wheat protein (WP) manufactured by a rapid prototyping technique to provide a micro/macro porous structure. Experimental groups were set based on the component ratio: (1) WP0% (m_MS:PCL:WP =30:70:0 weight per weight; w/w); (2) WP15% (m_MS:PCL:WP =30:55:15 w/w); (3) WP30% (m_MS:PCL:WP =30:40:30 w/w). RESULTS: Evaluation of the properties of fabricated scaffolds indicated that increasing the amount of WP improved the surface hydrophilicity and biodegradability of m_MS/PCL/WP composites, while reducing the mechanical strength. Moreover, experiments were performed to confirm the biocompatibility and osteogenic differentiation of human mesenchymal stem cells (MSCs) according to the component ratio of the scaffold. The results confirmed that the content of WP affects proliferation and osteogenic differentiation of MSCs. Based on the last day of the experiment, ie, the 14th day, the proliferation based on the amount of DNA was the best in the WP30% group, but all of the markers measured by PCR were the most expressed in the WP15% group. CONCLUSION: These results suggest that the m_MS/PCL/WP composite is a promising candidate for use as a scaffold in cell-based bone regeneration.

Role of PCSK9 in the Development of Mouse Periodontitis Before and After Treatment: A Double-Edged Sword.

Periodontitis is a highly prevalent infectious disease associated genetically with coronary heart disease (CHD). The effects of proprotein convertase subtilisin/kexin type 9 (PCSK9), a critical regulator of CHD, on periodontitis have not been studied to date. Here, we found that PCSK9 expression was increased in periodontitis patients and Porphyromonas gingivalis (Pg)-infected mice. Loss of PCSK9 attenuated Pg-induced periodontal bone loss in mice. First, PCSK9 deficiency reduced the release of inflammation-associated cytokines, such as tumor necrosis factor alpha (TNF-α) and interleukin 1ß, in vitro and in vivo. Second, its deficiency enhanced Pg and endotoxin clearance during Pg invasion in part by upregulating CD36 and low-density lipoprotein receptor (LDLR), respectively. However, after berberine treatment, periodontal bone regeneration in the PCSK9 knockout group was significantly lower than that in wild-type. This was because PCSK9 overexpression promoted osteogenic differentiation of periodontal ligament stem cells (PDLCs) prechallenged by TNF-α. Furthermore, PCSK9 could rescue PDLC osteogenesis by repressing the NF-κB signaling pathway by interacting with TRAF2. These results suggest that PCSK9 may be a potent drug target for treating periodontitis.

Characterization and osteogenic evaluation of mesoporous magnesium-calcium silicate/polycaprolactone/polybutylene succinate composite scaffolds fabricated by rapid prototyping.

The properties of scaffolds for bone tissue engineering, including their biocompatibility, highly interconnected porosity, and mechanical integrity, are critical for promoting cell adhesion, proliferation, and osteoinduction. We used various physical and biological assays to obtain in vitro confirmation that the proposed composite scaffolds are potentially suitable for applications to bone tissue engineering. The proposed new composite scaffolds, which we fabricated by a rapid prototyping technique, were composed of mesoporous magnesium-calcium silicate (m_MCS), polycaprolactone (PCL), and polybutylene succinate (PBSu). We systematically evaluated the characteristics of the composite scaffolds, such as the hydrophilicity and bioactivity. We also investigated the proliferation and osteogenic differentiation of human mesenchymal stem cells (MSCs) scaffolded on the m_MCS/PCL/PBSu composite. Our results showed that, compared to the m_MCS/PCL scaffold, the m_MCS/PCL/PBSu scaffold has improved water absorption, in vitro degradability, biocompatibility, and bioactivity in simulated body fluid, while its mechanical strength is reduced. Moreover, the results of the cytotoxicity tests specified in ISO 10993-12 and ISO 10993-5 clearly indicate that the m_MCS/PCL scaffold is not toxic to cells. In addition, we obtained significant increases in initial cell attachment and improvements to the osteogenic MSC differentiation by replacing the m_MCS/PCL scaffold with the m_MCS/PCL/PBSu scaffold. Our results indicate that the m_MCS/PCL/PBSu scaffold achieves enhanced bioactivity, degradability, cytocompatibility, and osteogenesis. As such, this scaffold is a potentially promising candidate for use in stem cell-based bone tissue engineering.

In vitro study on anti-inflammatory effects of epigallocatechin-3-gallate-loaded nano- and microscale particles.

PURPOSE: This study aimed to develop an anti-inflammation system consisting of epigallo-catechin-3-gallate (EGCG) encapsulated in poly(lactide-co-glycolic acid) (PLGA) particles to promote wound healing. METHODS: Nano- and microscale PLGA particles were fabricated using a water/oil/water emulsion solvent evaporation method. The optimal particle size was determined based on drug delivery efficiency and biocompatibility. The particles were loaded with EGCG. The anti-inflammatory effects of the particles were evaluated in an in vitro cell-based inflammation model. RESULTS: Nano- and microscale PLGA particles were produced. The microscale particles showed better biocompatibility than the nanoscale particles. In addition, the microscale particles released ~60% of the loaded drug, while the nanoscale particles released ~50%, within 48 hours. Thus, microscale particles were selected as the carriers. The optimal EGCG working concentration was determined based on the effects on cell viability and inflammation. A high EGCG dose (100 µM) resulted in poor cell viability; therefore, a lower dose (≤50 µM) was used. Moreover, 50 µM EGCG had a greater anti-inflammatory effect than 10 µM concentration on lipopolysaccharide-induced inflammation. Therefore, 50 µM EGCG was selected as the working dose. EGCG-loaded microparticles inhibited inflammation in human dermal fibroblasts. Interestingly, the inhibitory effects persisted after replacement of the drug-loaded particle suspension solution with fresh medium. CONCLUSION: The EGCG-loaded microscale particles are biocompatible and exert a sustained anti-inflammatory effect.

Mechanical stimuli modulate intracellular calcium oscillations: a pathological model without chemical cues.

OBJECTIVE: To control the oscillatory behavior of the intracellular calcium ([Ca2+]i) concentration in endothelial cells via mechanical factors (i.e., various hydrostatic pressures) because [Ca2+]i in these cells is affected by blood pressure. RESULTS: Quantitative analyses based on real-time imaging showed that [Ca2+]i oscillation frequency and relative concentration increased significantly when 200 mm Hg pressure, mimicking hypertension, was applied for >10 min. Peak height and peak width decreased significantly at 200 mm Hg. These trends were more marked as the duration of the 200 mm Hg pressure was increased. However, no change was observed under normal blood pressure conditions 100 mm Hg. CONCLUSION: We generated a simple in vitro model to study [Ca2+]i behavior in relation to various pathologies and diseases by eliminating possible complicating effects induced by chemical cues.

PCL/ß-TCP Composite Scaffolds Exhibit Positive Osteogenic Differentiation with Mechanical Stimulation.

We investigated the use of Polycaprolactone (PCL)/ ß-tricalcium phosphate (ß-TCP) composites with applied mechanical stimulation as scaffold for bone tissue engineering. PCL-based three-dimensional (3D) structures were fabricated in a solvent-free process using a 3D-printing technique. The mass fraction of ß-TCP was varied in the range 0-30%, and the structure and compressive modulus of the specimens was characterized. The shape and interconnectivity of the pores was found to be satisfactory, and the compressive modulus of the specimens was comparable with that of human trabecular bone. Human mesenchymal stem cells were seeded on the composites, and various biological evaluations were performed over 9 days. With a mass fraction of ß-TCP of 30%, differentiation began earlier; however, the cell proliferation rate was lower. Through the use of mechanical stimulation, however, the proliferation rate recovered, and was comparable with that of the other groups. This stimulation effect was also observed in ECM generation and other biological assays. With mechanical stimulation, expression of osteogenic markers was lower on samples with a ß-TCP content of 10 wt% than without ß-TCP; however, with mechanical stimulation, the sample with a ß-TCP content of 30 wt% exhibited significantly greater expression of those markers than the other samples. We found that mechanical stimulation and the addition of ß-TCP interacted closely, and that a mass fraction of ß-TCP of 30% was particularly useful as a bone tissue scaffold when accompanied by mechanical stimulation.

Ddit3 suppresses the differentiation of mouse chondroprogenitor cells.

Endochondral ossification is an essential skeletal development process which is strongly linked to chondrocyte differentiation. DNA damage-inducible transcript 3 (Ddit3), a member of the CCAAT/enhancer-binding protein family of transcription factors, is highly expressed in the cartilage plate. However, the role of DNA damage-inducible transcript 3 in chondrocyte differentiation remains to be investigated. Immunofluorescent staining was used to detect Ddit3 expression in the mouse growth plate and in the mouse chondroprogenitor cell line ATDC5. A lentivirus system was employed to overexpress Ddit3 and silence its endogenous expression in ATDC5 cells. The differentiation abilities of ATDC5 cells were examined through quantitative reverse transcription polymerase chain reaction (qRT-PCR) and chondrogenic and hypertrophic-related staining. Western blot analysis was performed to detect the protein expression of sex-determining region Y-type high-mobility group box 9 and CCAAT/enhancer-binding protein ß. Ddit3 was expressed in the proliferative and hypertrophic zones of the mouse growth plate. Ddit3 knockdown significantly enhanced the expression of chondrogenic and hypertrophic markers, whereas Ddit3 overexpression decreased the expression of these markers. This finding was also evidenced by Alcian blue staining, proteoglycan synthesis and alkaline phosphatase assay. Additionally, Ddit3 down-regulation significantly led to Sox9 up-regulation. These results suggest that Ddit3 suppresses the differentiation of ATDC5 cells. The function of Ddit3 might partially be regulated by Sox9 expression during chondrogenic and hypertrophic differentiation.

The effect of SIRT6 on the odontoblastic potential of human dental pulp cells.

INTRODUCTION: The aim of this study was to investigate whether SIRT6 is expressed in human dental pulp as well as the effect of SIRT6 on proliferation and odontoblastic differentiation of human dental pulp cells (HDPCs). METHODS: Immunohistochemical and immunocytochemical assays were used to detect the expression of SIRT6 in human dental pulp tissue and HDPCs. To determine the effect of SIRT6 on odontoblast differentiation, HDPCs with loss (HDPCs SIRT6 knockdown) and gain (HDPCs SIRT6 overexpression) of SIRT6 function were developed, and their proliferation ability was examined. Odontogenic differentiation of HDPCs was determined by alkaline phosphatase (ALP) activity, ALP-positive cell staining, alizarin red staining, and von Kossa staining. Mineralization-related genes, including ALP, dentin sialophosphoprotein (DSPP), and dentin matrix acidic phosphoprotein 1, were determined by real-time quantitative polymerase chain reaction. Western blot analysis was performed to detect the expression of DSPP protein. RESULTS: SIRT6 was found in the dental pulp tissue and HDPCs. SIRT6 knockdown decreased ALP activity in HDPCs; calcium nodule formation ability; and the expression of mineralization-related genes such as ALP, DSPP, and DMP1, whereas these were increased with the overexpression of SIRT6. CONCLUSIONS: SIRT6 is expressed in human dental pulp and participates in the odontoblast differentiation of HDPCs.

Failure rates of short (≤ 10 mm) dental implants and factors influencing their failure: a systematic review.

PURPOSE: The aim of this study was to evaluate the long-term failure rates of short dental implants (≤ 10 mm) and to analyze the influence of various factors on implant failure. MATERIALS AND METHODS: The PubMed and Cochrane Library databases were consulted for follow-up studies published between the years 1980 and 2009. For those studies that met the inclusion and exclusion criteria, data concerning the number of implants (≤ 10 mm) placed and lost and any related risk factors were gathered in tables and subjected to analysis. Univariate and multivariate analyses were performed. RESULTS: The heterogeneity and low quality of the included studies made meta-analysis impossible. A total of 35 human studies fulfilled the criteria. The studies included 14,722 implants, of which 659 failed. The total failure rate was 4.5%. The failure rates of implants with lengths of 6, 7, 7.5, 8, 8.5, 9, and 10 mm were 4.1%, 5.9%, 0%, 2.5%, 3.2%, 0.6%, and 6.5%, respectively. A majority (57.9%) of failures occurred before prosthesis connection. There was no statistically significant difference between the failure rates of short dental implants and standard implants or between those placed in a single stage and those placed in two stages (multivariate analysis). There was a tendency toward higher failure rates for the maxilla and for dental implants with a machined surface compared with the mandible and dental implants with a rough surface, respectively. CONCLUSIONS: Among the risk factors examined, most failures of short implants can be attributed to poor bone quality in the maxilla and a machined surface. Although short implants in atrophied jaws can achieve similar long-term prognoses as standard dental implants with a reasonable prosthetic design according to this review, stronger evidence is essential to confirm this finding.

[A cross-sectional survey on personality disorder in mental disorder outpatients in Shanghai].

OBJECTIVE: To study the prevalence and risk factors for personality disorder (PD) outpatients attending in for psychiatric and psychological counseling in Shanghai. METHODS: 3075 subjects were sampled by systematic sampling method from outpatients in psycho-counseling clinics and psychiatric clinics in Shanghai Mental Health Center. Based on DSM-IV criteria, personality disorders were assessed by both questionnaires (personality diagnostic questionnaire, PDQ-4+) and interviews (structured clinical interview for DSM-IV Axis II, SCID-II). Logistic regression analysis was performed to determine the significant independent contributor to PD. RESULTS: 71.3% of the outpatients were found having pathological personality by using questionnaire of self rating PD scale. 982 outpatients (31.9%) met criteria for at least one personality disorder by using structured clinical interview. Younger age (OR = 1.8, 95%CI: 1.5 - 2.1), single or divorced (OR = 1.6, 95%CI: 1.4 - 1.9), psychological counseling outpatients (OR = 1.2, 95%CI: 1.1 - 1.3), mood and outpatients with neurosis disorders (OR = 1.7, 95%CI: 1.4 - 2.0) were more frequently assigned as personality disorders. Data from logistic regression analysis showed that patients of tender age, not nurtured and raised by their parents, with introvert characters were related risk factors of PD. CONCLUSION: High prevalence rate of PD was found in this sample of Chinese outpatients, especially in those psychological counseling outpatients with mood or neurosis disorders. More attention should be paid to the recognition and intervention of PD in outpatients with mental disorders.

Desmoplastic ameloblastoma - A review.

Among the ameloblastomas, the desmoplastic variation is rare. The desmoplastic ameloblastoma (DA) is characterized by specific clinical, imaging, and histological features. The here presented retrospective analysis investigated the clinicoradiographic features of an overall of 115 DA-cases, having been reported in literature from 1984 to 2008. DA showed a nearly equal male to female ratio (55/59) with a prevalence within the forth and fifth decades. Sixty-two lesions occurred in the mandible and fifty-one lesions in the maxilla. Clinically, a painless swelling with buccal extension was the most common presentation being found in 48 cases. Radiologically, the lesion often presented multilocular (49.3%; 36/73), mixed radiolucent/radiopaque (55.6%; 50/90) and with ill-defined borders (64.0%; 48/75). Whereas enucleation provided a recurrence rate of 21.1%, resection reduced this rate remarkably to 3.1%. The average period until recurrence was 36.9 months. Histologically, scattered epithelial nests and extensively desmoplasia were prominent features of DA. In conclusion, these retrospective results confirm the statement that DA is a variation among ameloblastomas. DA present clinicoradiographic and histologic distinct features, when compared with "conventional ameloblastomas".

[Electrolytic coloration and spectral property of potassium bromide crystals].

Potassium bromide crystals were effectively colored electrolytically with a lab-made electrolytic apparatus at 693 K by applying a DC 1 200 V voltage. A lot of F, R, M and N type and some new unknown color centers were produced in the colored potassium bromide crystals, and the formation and transformation mechanisms of the color centers were presented. Spectral measurement and analysis were carried out systematically for the colored crystals, the spectral bands of corresponding color centers were reasonably resolved from the measured spectra, and the corresponding spectral parameters of the spectral bands were accurately determined by using spectral decomposition.