Three-dimensional graphene based passively mode-locked fiber laser

© 2014 Optical Society of America. We present an all-fiber passively mode-locked fiber laser incorporating three-dimensional (3D) graphene as a saturable absorber (SA) for the first time to the best of our knowledge. The 3D graphene is synthesized by template-directed chemical vapor deposition (CVD). The SA is then simply formed by sandwiching the freestanding 3D graphene between two conventional fiber connectors without any deposition process. It is demonstrated that such 3D graphene based SA is capable to produce high quality mode-locked pulses. A passively mode-locked fiber laser is constructed and stable output pulses with a fundamental repetition rate of ∼9.9 MHz and a pulse width of ∼1 ps are generated from the fiber laser. The average output power of the laser is ∼10.5 mW while the output pulse is operating at single pulse region. The results imply that the freestanding 3D graphene can be applied as an effective saturable absorption material for passively mode-locked lasers

Recovery of Lactobacillus casei strain Shirota (LcS) from faeces of healthy Singapore adults after intake of fermented milk

To validate survival of Lactobacillus casei strain Shirota (LcS) during passage through the gastrointestinal tract of healthy Singaporean young adults, 21 participants (18-25 years old) were asked to consume a 100 ml of fermented milk drink containing 1.0x10(8) cfu/ml of LcS daily for 14 days, and to maintain their dietary habit and life style. During and at the end of the ingestion period, both culture method (identity confirmed by ELISA) and 16s rRNA sequencing results revealed that viable LcS (7.27 and 7.64 log(10) cfu/g of faeces at the ingestion period Day 7 and Day 14, respectively) and Lactobacillus could be recovered from the faeces of all the subjects. The viable LcS count from male and female were comparable for each time point. Before consumption (baseline) and 14 days after cessation of consumption of the fermented milk, LcS was not detected in most of the subjects. In this study condition, the composition of the major gut microbiota (>0.1% in relative abundance of genus) and characteristics of defaecation such as stool consistency and frequency of defecation did not change throughout the study before and after ingestion of LcS. LcS was able to survive passage through the gastrointestinal tract of Singapore adults without sustainable colonisation, but the effect of LcS on microbiota modulation, stool consistency and frequency was not observed under this study condition

Impact of BRCA1/2 cascade testing on anxiety, depression, and cancer worry levels among unaffected relatives in a multiethnic Asian cohort

Cascade testing for families with BRCA pathogenic variants is important to identify relatives who are carriers. These relatives can benefit from appropriate risk management and preventative strategies arising from an inherited increased risk of breast, ovarian, prostate, melanoma, and pancreatic cancers. Cascade testing has the potential to enable cost-effective cancer control even in low- and middle-income settings, but few studies have hitherto evaluated the psychosocial impact of cascade testing in an Asian population, where the cultural and religious beliefs around inheritance and destiny have previously been shown to influence perception and attitudes toward screening. In this study, we evaluated the short- and long-term psychosocial impact of genetic testing among unaffected relatives of probands identified through the Malaysian Breast Cancer Genetics Study and the Malaysian Ovarian Cancer Study, using validated questionnaires (Hospital Anxiety and Depression Scale and Cancer Worry Scale) administered at baseline, and 1-month and 2-year post-disclosure of results. Of the 305 unaffected relatives from 98 independent families who were offered cascade testing, 256 (84%) completed predictive testing and family history of cancers was the only factor significantly associated with uptake of predictive testing. We found that the levels of anxiety, depression, and cancer worry among unaffected relatives decreased significantly after result disclosure and remained low 2-year post-result disclosure. Younger relatives and relatives of Malay descent had higher cancer worry at both baseline and after result disclosure compared to those of Chinese and Indian descent, whereas relatives of Indian descent and those with family history of cancers had higher anxiety and depression levels post-result disclosure. Taken together, the results from this Asian cohort highlight the differences in psychosocial needs in different communities and inform the development of culture-specific genetic counseling strategies

FOXM1 Upregulation Is an Early Event in Human Squamous Cell Carcinoma and it Is Enhanced by Nicotine during Malignant Transformation

Cancer associated with smoking and drinking remains a serious health problem worldwide. The survival of patients is very poor due to the lack of effective early biomarkers. FOXM1 overexpression is linked to the majority of human cancers but its mechanism remains unclear in head and neck squamous cell carcinoma (HNSCC).FOXM1 mRNA and protein expressions were investigated in four independent cohorts (total 75 patients) consisting of normal, premalignant and HNSCC tissues and cells using quantitative PCR (qPCR), expression microarray, immunohistochemistry and immunocytochemistry. Effect of putative oral carcinogens on FOXM1 transcriptional activity was dose-dependently assayed and confirmed using a FOXM1-specific luciferase reporter system, qPCR, immunoblotting and short-hairpin RNA interference. Genome-wide single nucleotide polymorphism (SNP) array was used to 'trace' the genomic instability signature pattern in 8 clonal lines of FOXM1-induced malignant human oral keratinocytes. Furthermore, acute FOXM1 upregulation in primary oral keratinocytes directly induced genomic instability. We have shown for the first time that overexpression of FOXM1 precedes HNSCC malignancy. Screening putative carcinogens in human oral keratinocytes surprisingly showed that nicotine, which is not perceived to be a human carcinogen, directly induced FOXM1 mRNA, protein stabilisation and transcriptional activity at concentrations relevant to tobacco chewers. Importantly, nicotine also augmented FOXM1-induced transformation of human oral keratinocytes. A centrosomal protein CEP55 and a DNA helicase/putative stem cell marker HELLS, both located within a consensus loci (10q23), were found to be novel targets of FOXM1 and their expression correlated tightly with HNSCC progression.This study cautions the potential co-carcinogenic effect of nicotine in tobacco replacement therapies. We hypothesise that aberrant upregulation of FOXM1 may be inducing genomic instability through a program of malignant transformation involving the activation of CEP55 and HELLS which may facilitate aberrant mitosis and epigenetic modifications. Our finding that FOXM1 is upregulated early during oral cancer progression renders FOXM1 an attractive diagnostic biomarker for early cancer detection and its candidate mechanistic targets, CEP55 and HELLS, as indicators of malignant conversion and progression

Dimensional crossover in topological matter: Evolution of the multiple Dirac point in the layered system to the flat band on the surface

We consider the dimensional crossover in the topological matter, which involves the transformation of different types of topologically protected zeroes in the fermionic spectrum. In the considered case, the multiple Dirac (Fermi) point in quasi 2-dimensional system evolves into the flat band on the surface of the 3-dimensional system when the number of atomic layers increases. This is accompanied by formation of the spiral nodal lines in the bulk. We also discuss the topological quantum phase transition at which the surface flat band shrinks and changes its chirality, while the nodal spiral changes its helicity.Comment: 13 pages, 7 figure

On the minima and convexity of Epstein Zeta function

Let $Z_n(s; a_1,..., a_n)$ be the Epstein zeta function defined as the meromorphic continuation of the function \sum_{k\in\Z^n\setminus\{0\}}(\sum_{i=1}^n [a_i k_i]^2)^{-s}, \text{Re} s>\frac{n}{2} to the complex plane. We show that for fixed $s\neq n/2$, the function $Z_n(s; a_1,..., a_n)$, as a function of $(a_1,..., a_n)\in (\R^+)^n$ with fixed $\prod_{i=1}^n a_i$, has a unique minimum at the point $a_1=...=a_n$. When $\sum_{i=1}^n c_i$ is fixed, the function $$(c_1,..., c_n)\mapsto Z_n(s; e^{c_1},..., e^{c_n})$$ can be shown to be a convex function of any $(n-1)$ of the variables $\{c_1,...,c_n\}$. These results are then applied to the study of the sign of $Z_n(s; a_1,..., a_n)$ when $s$ is in the critical range $(0, n/2)$. It is shown that when $1\leq n\leq 9$, $Z_n(s; a_1,..., a_n)$ as a function of $(a_1,..., a_n)\in (\R^+)^n$, can be both positive and negative for every $s\in (0,n/2)$. When $n\geq 10$, there are some open subsets $I_{n,+}$ of $s\in(0,n/2)$, where $Z_{n}(s; a_1,..., a_n)$ is positive for all $(a_1,..., a_n)\in(\R^+)^n$. By regarding $Z_n(s; a_1,..., a_n)$ as a function of $s$, we find that when $n\geq 10$, the generalized Riemann hypothesis is false for all $(a_1,...,a_n)$.Comment: 27 page

Effect of remote ischemic preConditioning on liver injury in patients undergoing liver resection: the ERIC-LIVER trial

OBJECTIVE: Novel hepatoprotective strategies are needed to improve clinical outcomes during liver surgery. There is mixed data on the role of remote ischemic preconditioning (RIPC). We investigated RIPC in partial hepatectomy for primary hepatocellular carcinoma (HCC). METHODS: This was a Phase II, single-center, sham-controlled, randomized controlled trial (RCT). The primary hypothesis was that RIPC would reduce acute liver injury following surgery indicated by serum alanine transferase (ALT) 24 h following hepatectomy in patients with primary HCC, compared to sham. Patients were randomized to receive either four cycles of 5 min/5 min arm cuff inflation/deflation immediately prior to surgery, or sham. Secondary endpoints included clinical, biochemical and pathological outcomes. Liver function measured by Indocyanine Green pulse densitometry was performed in a subset of patients. RESULTS: 24 and 26 patients were randomized to RIPC and control groups respectively. The groups were balanced for baseline characteristics, except the duration of operation was longer in the RIPC group. Median ALT at 24 h was similar between groups (196 IU/L IQR 113.5-419.5 versus 172.5 IU/L IQR 115-298 respectively, p = 0.61). Groups were similar in secondary endpoints. CONCLUSION: This RCT did not demonstrate beneficial effects with RIPC on serum ALT levels 24 h after partial hepatectomy