Preparation and evaluation of a biomimetic scaffold with porosity gradients in vitro

A novel biodegradable scaffold based on mimetic a natural bone tissue morphology with a porosity gradient structure was prepared in this paper. The result of surface morphology indicated that a graded porous structure was formed in the fabricated scaffold, where the dense layer (0%) was connected with the most porous layer (60%) by a middling porous layer (30%). To evaluate the degradability, graded porous scaffolds compared with homogeneous scaffolds were placed into a Tris-HCl buffer solution (pH = 7.4) for 28 days. It was found that both scaffolds presented the same degradation trend, and the graded porous structure did not change the original degradability of the scaffold. Moreover, the compressive strength of the graded porous scaffold was better than that of conventional homogeneous scaffold with the increase of degradation time, and the graded porous structure can enhanced the mechanical property of the scaffold. These findings suggest that this biodegradable and porosity-graded scaffold may be a new promising scaffold for loaded bone implant.

A comparison of the clinical characteristics of women with recurrent major depression with and without suicidal symptomatology

BACKGROUND

The relationship between recurrent major depression (MD) in women and suicidality is complex. We investigated the extent to which patients who suffered with various forms of suicidal symptomatology can be distinguished from those subjects without such symptoms.

METHOD

We examined the clinical features of the worst episode in 1970 Han Chinese women with recurrent DSM-IV MD between the ages of 30 and 60 years from across China. Student's t tests, and logistic and multiple logistic regression models were used to determine the association between suicidality and other clinical features of MD.

RESULTS

Suicidal symptomatology is significantly associated with a more severe form of MD, as indexed by both the number of episodes and number of MD symptoms. Patients reporting suicidal thoughts, plans or attempts experienced a significantly greater number of stressful life events. The depressive symptom most strongly associated with lifetime suicide attempt was feelings of worthlessness (odds ratio 4.25, 95% confidence interval 2.9-6.3). Excessive guilt, diminished concentration and impaired decision-making were also significantly associated with a suicide attempt.

CONCLUSIONS

This study contributes to the existing literature on risk factors for suicidal symptomatology in depressed women. Identifying specific depressive symptoms and co-morbid psychiatric disorders may help improve the clinical assessment of suicide risk in depressed patients. These findings could be helpful in identifying those who need more intense treatment strategies in order to prevent suicide.

Significance of CD4 T-cell adenosine triphosphate levels monitoring in elderly renal transplant recipients

OBJECTIVES

To find the significance of CD4 T-cell adenosine triphosphate (ATP) levels in elderly renal recipients in correlation with drug doses, levels, and clinical parameters.

METHODS

Drug doses and levels, CD4 T-cell ATP level (162 sequential samples), and other clinical data were collected and assessed among 31 elderly renal recipients who underwent transplantations from November 2007 to March 2011.

RESULTS

Among subjects with stable clinical status, the main ATP levels pretransplantation were not significantly different from those posttransplantation: 302.4 ± 97.5 ng/mL versus 288.8 ± 102.6 ng/mL (P > .05). There was no relationship between ATP levels and tacrolimus concentrations or doses. In 12 patients experiencing infection, the ATP levels were significantly lower then those of subjects showing a stable clinical status: 127.3 ± 92.8 versus 288.8 ± 102.6 ng/mL (P < .01). Six patients with biopsy-proven acute rejection episodes did not show significantly higher ATP levels compared with those who were clinically stable: 26.2 ± 224.8 versus 288.8 ± 102.6 (P > .05).

CONCLUSIONS

CD4 T-cell ATP levels were valuable to monitor immunosuppression among elderly renal transplant recipients.

Evidence for the direct two-photon transition from ψ(3686) to J/ψ

The two-photon transition ψ(3686)→γγJ/ψ is studied in a sample of 1.06×10(8) ψ(3686) decays collected by the BESIII detector. The branching fraction is measured to be (3.1±0.6(stat)(-1.0)(+0.8)(syst))×10(-4) using J/ψ→e(+)e(-) and J/ψ→μ(+)μ(-) decays, and its upper limit is estimated to be 4.5×10(-4) at the 90% confidence level. This work represents the first measurement of a two-photon transition among charmonium states. The orientation of the ψ(3686) decay plane and the J/ψ polarization in this decay are also studied. In addition, the product branching fractions of sequential E1 transitions ψ(3686)→γχ(cJ) and χ(cJ)→γJ/ψ(J=0,1,2) are reported.

Observation of phonon sideband emission in intrinsic InN nanowires: a photoluminescence and micro-Raman scattering study

In this work, photoluminescence and micro-Raman scattering experiments were performed on undoped InN nanowires. It was found that, besides the main photoluminescence peak, a clear phonon sideband emission peak, with an extremely narrow linewidth ~9 meV, was measured. The phonon spectrum revealed by micro-Raman scattering indicates only uncoupled LO phonons are involved in such phonon sideband emission. The clearly resolved phonon sideband emission peak with a narrow linewidth, together with the uncoupled LO phonon modes, suggests the superior quality of the presented InN nanowires, i.e., extremely low residual electron density and the absence of surface electron accumulation, which is consistent with the physical properties of intrinsic InN nanowires as in the previous studies. The detailed phonon sideband properties are also discussed in the text.

Is premature ovarian ageing a cause of unexplained recurrent miscarriage?

Recurrent miscarriage is often unexplained. In our study, we test the hypothesis that unexplained recurrent miscarriage is associated with premature ovarian ageing by comparing the basal follicle-stimulating hormone (FSH) level between women with recurrent miscarriage and a control group of subjects in two different ethnic centres: one in Guangzhou, China and the other in Sheffield, UK. The subjects were stratified into three different age groups, and all of them were under the age of 40 years. We found no significant difference in basal FSH level between the subjects and the control groups, and the proportion of women with high FSH (>10 IU/l) was higher in the Guangzhou cohort but not in the Sheffield cohort. Our observation suggests that premature ovarian ageing is not a significant contributory factor of recurrent miscarriage, but a study on the ethnic variation in the aetiology of recurrent miscarriage is needed.

Dysregulation of transforming growth factor-beta 1 expression in N-nitrosomethylbenzylamine-induced rat esophageal tumorigenesis

Alterations in the expression of transforming growth factor-beta 1 (TGF-beta 1) have been implicated for malignancies of both human and experimental animal models. To further investigate the role of TGF-beta 1 in chemically-induced esophageal tumorigenesis, the expression of TGF-beta 1 was analyzed by reverse transcription-polymerase chain reaction (T-PCR) and immunohistochemical studies in N-nitrosomethylbenzylamine (NMBA)-induced rat esophageal tumorigenesis. We observed no significant difference in TGF-beta 1 mRNA levels between 25-week papillomas and normal rat esophageal epithelium. However, TGF-beta 1 mRNA levels were increased 2.9-fold (p<0.05) in 45-week papillomas induced by NMBA, when compared to normal rat esophageal epithelium. Immunohistochemical studies revealed a decreased intracellular TGF-beta 1 immunoreactivity in the papillomas when compared to the normal rat esophageal epithelium, indicating the existence of a discordance between TGF-beta 1 mRNA and protein expression. Furthermore, by immunohistochemical staining of proliferating cell nuclear antigen (PCNA), a predominantely mutually exclusive staining pattern was observed for TGF-beta 1 and PCNA. These findings suggest that overexpression of TGF-beta 1 mRNA occurs late in NMBA-induced rat esophageal tumorigenesis, and the discordant mRNA and protein expression may result in tumor evasion from TGF-beta 1 controlled negative growth regulation, thus promoting tumor progression in this model.

[Growth inhibition of transfection of p16 gene to lung adenocarcinoma cell lines Anip973 and AGZY83-a]

BACKGROUND

To investigate the suppression effect of tumor suppressor gene p16 on lung adenocarcinoma cell lines.

METHODS

p16 expression vector was transfected into high metastasis lung carcinoma cell line, Anip973, and low metastasis lung cancer cell line, AGZY83-a. The suppression effects of p16 gene on cell growth was detected by cell growth curve, cloning efficiency assay, flow cytometry analysis and TUNEL technique.

RESULTS

Overexpression of p16 gene in Anip973 and AGZY83-a could only lead the cells to arrest at G1 phase, but had no effects on cell growth curves, colony for mation rate and apoptosis.

CONCLUSIONS

Overexpression of p16 in Anip973 and AGZY83-a can not suppress the growth of the tumor cells.

Accelerated cellular senescence in solid tumor therapy

Accelerated cellular senescence (ACS) is an emerging concept that implicates sustained, telomere-independent cell cycle arrest of neoplastic cells in response to chemotherapeutic agents, ionizing radiation, oxidative stress, or the presence of selective oncogenic stimuli. Recent evidence suggests that a subset of tumor cells induced in a state of reversible ACS can escape cell cycle arrest and resume proliferation accounting for cancer progression. The purpose of this review is to describe our current understanding of ACS including signaling pathways of senescence escape, role of senescence biomarkers, and rationale for senescence-based therapy. This article is part of a Special Issue entitled "Apoptosis: Four Decades Later".

A dynamic plasmonic manipulation technique assisted by phase modulation of an incident optical vortex beam

A novel phase modulation method for dynamic manipulation of surface plasmon polaritons (SPPs) with a phase engineered optical vortex (OV) beam illuminating on nanoslits is experimentally demonstrated. Because of the unique helical phase carried by an OV beam, dynamic control of SPP multiple focusing and standing wave generation is realized by changing the OV beam's topological charge constituent with the help of a liquid-crystal spatial light modulator. Measurement of SPP distributions with near-field scanning optical microscopy showed an excellent agreement with numerical predictions. The proposed phase modulation technique for manipulating SPPs features has seemingly dynamic and reconfigurable advantages, with profound potential for development of SPP coupling, routing, multiplexing and high-resolution imaging devices on plasmonic chips.

Gene Detection With Carbon Nanotubes

The potential of carbon nanotubes (CNTs) as nanosensors in detection of genes through a vibration analysis is investigated with molecular dynamics. The carbon nanotube based nanosensor under investigation is wrapped by a gene whose structure includes a single strand deoxyribose nucleic acid (DNA) with a certain number of distinct nucleobases. Different genes are differentiated or detected by identifying a differentiable sensitivity index that is defined to be the shifts of the resonant frequency of the nanotube. Simulation results indicate that the nanosensor is able to differentiate distinct genes, i.e., small proline-rich protein 2 A, small proline-rich protein 2B, small proline-rich protein 2D, and small proline-rich protein 2E, with a recognizable sensitivity. The research provides a rapid, effective, and practical method for detection of genes.