Control of molecular rotors by selection of anchoring sites

We demonstrate a new method to switch on and off the rotational motion of a long-chain molecule by controlling the bonding geometry between the molecule and a substrate. An azobenzene derivative molecule adsorbed on a Au(111) surface is immobile only when its three rotation centers, comprised of two phenyl rings and a nitrogen-nitrogen bond, are located at hollow sites of the Au(111) surface, as observed by scanning tunneling microscopy. Rotational motion can be activated by exciting the vibrational modes and inducing hopping motion away from the immobile site with a voltage pulse.

Variation of human papillomavirus 16 in cervical and lung cancers in Sichuan, China

Although the crucial role of human papillomaviruses (HPVs), especially HPV-16 in various cancers has been confirmed, the variation of HPV-16 among different cancers have not been investigated in a specific geographic location. In order to elucidate whether similar HPV-16 variants are involved in different kinds of cancers in the same geographic location, the analysis of sequence variants of E6 and E7 oncogenes and L1 gene of HPV-16 in cervical and lung cancers in Sichuan, China, was carried out. Tissue samples from 122 cervical cancers, 104 lung cancers, and 138 controls were subjected to RT-PCR or PCR, sequencing, and sequence analysis. The infection rates of HPV-16 in cervical, lung cancers, and non-malignant controls were 68.9%, 17.3%, and 37.0%, respectively. Asian prototype variants prevailed in cervical and lung cancers, while European prototype variants in non-malignant controls. In comparison to the lung cancer, cervical cancer showed a much higher diversity of HPV-16 oncogenes. These results indicate that in Sichuan, China, Asian prototype variants of HPV-16 are more pathogenic than their European counterparts.

Basiliximab or antithymocyte globulin for induction therapy in kidney transplantation: a meta-analysis

OBJECTIVE

To compare efficacy and safety of basiliximab versus antithymocyte globulin (ATG) for induction therapy in kidney transplantation.

METHODS

A literature search of the MEDLINE, EMBASE, CBMdisc, and Cochrane databases was used to identify randomized controlled trials that compared basiliximab and ATG for induction therapy in kidney transplantation. Inclusion criteria comprised: prospective randomized controlled clinical trials, follow-up time >or=12 months, randomized comparisons of ATG versus basiliximab as induction therapy in kidney transplantation. Meta-analytical techniques were applied to identify differences in outcomes between the two agents.

RESULTS

A total of six studies involving 853 patients were identified. No differences between ATG and basiliximab were seen in terms of biopsy-proven rejection (relative risk [RR] 1.15, 95% confidence interval [CI] 0.88-1.52, P = .31), delayed graft function (RR 1.02, 95% CI 0.69-1.51, P = .93), graft loss (RR 1.15, 95% CI 0.73-1.80, P = .55), and patient death (RR 1.22, 95% CI 0.65-2.30, P = .54). But basiliximab had a lower incidence of infection (RR 0.87, 95% CI 0.78-0.97, P = .02) and neoplasm (RR 0.29, 95% CI 0.09-0.97, P = .04).

CONCLUSIONS

Basiliximab is as effective as ATG for induction therapy in kidney transplantation, whereas basiliximab has a lower incidence of infection. Basiliximab may be a safer and preferable option for induction therapy in kidney transplantation.

Enhanced thermal stability of monodispersed silver cluster arrays assembled on block copolymer scaffolds

Triblock copolymer poly(styrene-b-butadiene-b-styrene) (SBS) films with long-range ordered self-assembled nanopatterns are used as templates to selectively adsorb soft-landing silver clusters. Closely spaced cluster arrays with high monodispersity are formed through the confinement of the block copolymer scaffolds, and show a much enhanced thermal stability as compared with the cluster assemblies on the surfaces of covalent amorphous solids, or even on the disordered SBS films. Their morphologies are barely influenced by long time thermal annealing at a temperature as high as 180 degrees C, while in the latter case intense aggregations and coalescences of silver clusters are commonly observed upon annealing. The different thermal stabilities of the cluster assemblies also induce different evolutions of their optical extinction spectra under annealing. This promises a simple way to control the monodispersity and thermal stability of metal cluster assembly via self-assembled block copolymer template.

Estimated PBDE and PBB Congeners in soil from an electronics waste disposal site

This study estimated PBDE and PBB congener emissions into the environment from three different e-waste disposal sites that consisted of rude broilers (RB), acid baths (AB) and end-up dumps (ED). Different PBDE and PBB congener profiles were analyzed, and some of their emission sources were discussed. For the examined sites, the levels of SigmaPBB and SigmaPBDE were highest at ED (SigmaPBB 1943.86 ng/g, dw; SigmaPBDE 990.87 ng/g, dw), followed by RB (SigmaPBB 704.58 ng/g, dw; SigmaPBDE 799.27 ng/g, dw) and finally AB (SigmaPBB 108.78 ng/g, dw; SigmaPBDE 171.18 ng/g, dw). PBE-209 (AB 48.67 ng/g, 28.43%; RB 160.23 ng/g, 20.05%; ED 234.12 ng/g, 23.63%) and PBE-203 (AB 51.23 ng/g, 29.93%; RB 130.34 ng/g, 16.31%; ED 93.41 ng/g, 9.43%) exhibited the highest concentrations when compared to the other congeners. Furthermore, high levels of deca-BDE (BDE-209) were observed in AB (48.67 ng/g, 28.43%) and RB sites (160.23 ng/g, 20.05%), which was in accordance with the large amount of these materials in electronics products in China.

The effects of antipsychotic drugs administration on 5-HT1A receptor expression in the limbic system of the rat brain

Increasing evidence suggests that 5-HT1A receptors are involved in the pathophysiology and treatment of schizophrenia. This paper investigated 5-HT1A receptor mRNA expression and binding density in female rats treated with aripiprazole (2.25 mg/kg/day), olanzapine (1.5 mg/kg/day), haloperidol (0.3 mg/kg/day) or vehicle (control) orally three times/day for 1 or 12 weeks. Animals were sacrificed 48 h after the last administration. Aripiprazole significantly increased 5-HT1A receptor binding density by 33% in the CA1 region of the hippocampus and by 21% in the medial posterodorsal nuclei of posterior amygdala (MeP) compared to the control group after 1 week of treatment. Olanzapine significantly decreased 5-HT1A receptor binding density by 17-22% in Layers I-IV of the cingulate cortex after 1 week of treatment. Neither of these antipsychotic drugs affected 5-HT1A receptor binding density after 12 weeks drug treatment. As expected, haloperidol treatment did not have any significant effect on 5-HT1A binding density after 1 or 12 weeks of treatment. 5-HT1A receptor mRNA expression was not altered by antipsychotic treatment in any brain region. The results indicate that aripiprazole and olanzapine have differential effects on 5-HT1A receptor expression, which may contribute to their distinct profiles in improving negative symptoms and cognitive deficits in schizophrenia. Aripiprazole and olanzapine may produce adaptation and desensitization of 5-HT1A receptor expression after long term treatment.

Predicting the long-term risk of prostate cancer-specific mortality after radical prostatectomy

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Background: Nomograms that predict prostate-specific antigen (PSA) defined biochemical recurrence (BCR) of prostate cancer after radical prostatectomy are the most widely used prediction tools in oncology for treatment decision making and counseling. While BCR universally antedates prostate cancer-specific mortality (PCSM), it is a limited surrogate endpoint due to its variable natural history. Nomograms that accurately predict the risk of PCSM are needed. Methods: Using Fine and Gray competing risk regression analysis, the clinical data and follow-up information of 11,521 patients treated with radical prostatectomy at four academic centers from 1987 to 2005 were modeled to predict PCSM. The model was externally validated on 12,893 patients treated at a separate institution during the same period. Results: The 15-year PCSM and all-cause mortality was 7% and 33%, respectively. The 15-year PCSM for patients with final pathological Gleason score 2–6, 3+4, 4+3, and 8–10 was 1%, 7%, 8%, and 49%, respectively. By pathologic stage, the risks were 2%, 7%, 29%, and 23% for organ-confined, extraprostatic extension, seminal vesicle invasion, and lymph node-positive prostate cancer. Of 3756 patients with organ-confined and Gleason 2–6 cancer, only 1 (0.03%) died from prostate cancer. Primary and secondary Gleason grade (p < 0.001 for both), seminal vesicle invasion (p < 0.001), and year of surgery (p = 0.002) were significant predictors of PCSM. A nomogram predicting 15-year PCSM based on pathologic parameters was accurate and discriminating with an externally-validated concordance index of 0.92. Conclusions: A nomogram has been constructed that predicts the long-term risk of PCSM after radical prostatectomy based on the pathologic grade and stage of the cancer. The presence of poorly differentiated cancer and seminal vesicle invasion are the prime determinants of PCSM. Our study suggests that biomarkers may have limited empiric prognostic utility as PCSM can be accurately predicted once the pathologic features of prostate cancer are known.

No significant financial relationships to disclose.

Survival following early hormone therapy for men with rapid PSA doubling time within 2 years following radical prostatectomy

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Background: Early hormonal therapy has been used in the salvage setting for men with biochemical recurrence following radical prostatectomy (RP), but no studies to date have been able to evaluate whether such treatment prolongs survival. We examined the impact of salvage hormonal therapy on overall survival (OS) in a cohort with long-term follow-up, and attempted to identify the subgroup most likely to benefit. Methods: Retrospective analysis of a cohort of 488 men undergoing RP at Johns Hopkins Hospital from 1982–2004, who experienced biochemical recurrence and received no salvage therapy (n = 386) or salvage hormonal therapy (n = 102); no one received adjuvant therapy. Survival was defined from biochemical recurrence to death from all causes, and analyzed with proportional hazards models with time-dependent covariates. Results: With median follow-up of 6 years after recurrence and 9 years after RP, there were 143 deaths (29%), including 105 from prostate cancer. After adjusting for PSA doubling time (PSADT), RP Gleason score, and year of surgery, hormonal therapy did not significantly improve OS for all men, compared to no salvage therapy: hazard ratio (HR) = 0.72 (95% confidence interval (CI): 0.45–1.17), p = 0.187. However, when restricted to men with early recurrence, i.e. within 2 years of RP, and with a rapid PSADT<6 months, hormonal therapy was associated with a large, significant improvement in OS: HR = 0.25 (95% CI: 0.08–0.71), p = 0.0095. This subgroup comprised 22% of the cohort. In contrast, there was no benefit of salvage hormonal therapy in men with early recurrence and PSADT>6 months: HR = 1.96 (95% CI: 0.89–4.31), p = 0.093, nor those who recurred more than 2 years after RP, regardless of PSADT. Conclusions: This study suggests that early salvage hormonal therapy may significantly and substantially prolong overall survival in the subgroup of men who experience an early biochemical recurrence with a rapid PSADT. These results are consistent with early recurrences being indicative of metastatic disease, while later recurrences are more likely to represent local recurrence. If validated, these results may provide useful stratification criteria for clinical trials.

No significant financial relationships to disclose.

Deviation from Archie's law in partially saturated porous media: Wetting film versus disconnectedness of the conducting phase

We experimentally study the electrical transport in partially water-saturated pore network. The porous medium under investigation is a Fontainebleau sandstone, characterized by x-ray tomography. We show the existence of two electrical conductivity regimes. At high water saturation, the electric resistivity follows a well-known Archie law. Below a water saturation S_{w} approximately 0.2 , a strong negative deviation from this Archie law is observed. We attribute this transition to the existence of "a thick liquid film," assuring the ionic conduction in the low saturation regime. A numerical simulation is proposed to confirm this scenario. Two possible protocols are used to distribute the brine phase in the pore network of a three-dimensional microtomography image. The first one is based on a minimization of the interfacial energy. The second takes into account a quasistatic capillary displacement. The classical random-walk algorithm is used to compute the electric conductivity at various water saturations. Without the "thick film," both of the two fluid-placing protocols show a disconnectedness transition of the brine phase when S_{w}<0.2 . Adding this "film" to solid surface, the electrical continuity is maintained. The bending down trend is correctly reproduced, showing that in this range, the electric response cannot be described by a power law as usual.

Local structural and electrical properties of ferroelectric Bi3.25La0.75Ti3O12 thin films on Pt

Ferroelectric Bi3.25La0.75Ti3O12 (BLT) thin films have been grown by a sol-gel method. Annealing conditions after the drying process have been explored over a wide range of temperature. BLT thin films prepared on Pt/TiO2 coated SiO2/Si(100) were investigated by Raman scattering spectroscopy, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy. Raman spectra reveal the growth route of phase-formation of the BLT films. Ferroelectric domains in the thin films are observed by using AFM, registering the electrostatic force response of the thin films in the presence of a low ac field. It is found that the as-grown domain configuration and switching behavior are strongly dependent on growth temperature. Depth-profiling of the electronic states of Bi, Ti, and La atoms shows the oxidation during the growth.

Mismatch repair gene mutations in Chinese HNPCC patients

To explore the characteristics of DNA mismatch repair gene mutations in Chinese patients with hereditary non-polyposis colorectal cancer (HNPCC) or Lynch syndrome, the MLH1 and MSH2 genes from probands of 76 HNPCC families were sequenced. By doing so, two frame-shift mutations, three splice-site mutations and fourteen missense mutations (thirteen missense mutations and one nonsense mutation) were identified in the MLH1 gene. In addition, one splice-site mutation and six missense mutations were detected in the MSH2 gene. None of these mutations were detected in 100 matched healthy controls. The remaining mutation-negative cases were subjected to large fragment deletion analysis using multiplex ligation-dependent probe amplification (MLPA). By doing so, five large fragment deletions were detected in the MSH2 gene. No large fragment deletions were detected in the MLH1 gene. We conclude that the MLH1 and MSH2 genes in Chinese HNPCC families exhibit broad mutation spectra.