Emittance-exchange-based high harmonic generation scheme for a short-wavelength free electron laser

Generation of short-wavelength radiation by a free-electron laser using up-frequency conversion of an electron bunch density modulation is currently an area of active research. We propose a new scheme for producing the longitudinal electron bunch density modulation similar to the recently proposed echo-enabled harmonic generation but based on an emittance exchange beam line and a multislit mask. Beam line analysis and start-to-end simulation are presented.

Achalasia: incidence, prevalence and survival. A population-based study

BACKGROUND

Studies of achalasia epidemiology are important as they often yield new insights into disease etiology. In this study, our objective was to carry out the first North American population-based study of achalasia epidemiology using a governmental administrative database.

METHODS

All residents in the province of Alberta, Canada receive universal healthcare coverage as a benefit. The provincial health ministry, Alberta Health and Wellness, maintains a central stakeholder database of patient demographic information and physician billing claims. We defined an achalasia case as a billing claim submitted for the years 1996-2007 with an ICD-9-CM code of 530.0 or 530 and a Canadian Classification of Procedure treatment code of 54.92A (endoscopic balloon dilation) or 54.6 (esophagomyotomy). A preliminary validation study of the case definition demonstrated a sensitivity of 85% and specificity of 99% for known cases and controls.

KEY RESULTS

A total of 463 achalasia cases were identified from 1995 to 2008 (59.6% males). Mean age at diagnosis was 53.1 years. In 2007, the achalasia incidence was 1.63/100,000 (95% CI 1.20, 2.06) and the prevalence was 10.82/100,000 (95% CI 9.70, 11.93). We observed a steady increase in the overall prevalence rate from 2.51/100,000 in 1996 to 10.82/100,000 in 2007. Survival of achalasia cases was significantly less than age-sex matched population controls (P < 0.0001).

CONCLUSIONS & INFERENCES

Using a population-based approach, the incidence and prevalence of treated achalasia is 1.63/100,000 and 10.82/100,000, respectively. The disease appears to have a stable incidence but a rising prevalence. Survival of achalasia cases is significantly less than age-matched healthy controls.

The profile of KIR3DL1 and KIR3DS1 alleles in an African American population resembles that found in African populations

KIR3DL1 and KIR3DS1 allele frequencies were determined by DNA sequencing of the complete coding regions from 100 random unrelated African Americans. Alleles 3DL1*01501 (29 individuals) and 3DL1*01502 (23 individuals) were most frequently observed in addition to 21 other known alleles and 7 new alleles: KIR3DL1*01503, *03102, *064, *065, *066, *067, and *068. Two of the new alleles (KIR3DL1*064, *065) created additional variants of the chimeric KIR3DL1/KIR3DL2 gene. KIR3DS1*01301 (94% of the gene positive individuals) and KIR3DS1*049N (11%) were identified in the 18 individuals carrying this gene. Three individuals appeared to carry a killer cell immunoglobulin-like receptor haplotype with KIR3DL1/S1 duplication. The profile of alleles resembles that found in African populations but also shows signs of admixture.

Serological surveillance of influenza A virus infection in swine populations in Fujian province, China: no evidence of naturally occurring H5N1 infection in pigs

Several highly pathogenic H5N1 avian influenza viruses were isolated from swine populations in Fujian Province, China, since 2001. Because it is thought that H5N1 infection in pigs might result in virus adaptation to humans, we surveyed swine populations in Fujian Province in 2004 and 2007 for serological evidence of the infection. Twenty-five pig farms covering all nine administrative districts of Fujian Province were sampled and a total of 1407 serum specimens were collected. The haemagglutination inhibition (HI) tests revealed no evidence of H5 infection and only a few cases of H9 infection. The negative results for H5 infection were further verified by micro-neutralization tests. By contrast, H1 influenza virus infections were prevalent in swine in both surveys according to the results of enzyme-linked immunosorbent assay (ELISA). The H3 infection rate was reduced dramatically in 2007 compared with 2004, when examined by HI and ELISA. In summary, the results imply that the swine populations in Fujian Province had not been affected greatly by the H5N1 avian influenza virus, given that there is no serological evidence that H5N1 influenza virus has infected the pig populations. The reported isolates represent only sporadic cases.

African Americans exhibit a predominant allele in the midst of extensive KIR2DL1 allelic diversity

KIR2DL1 alleles were identified by DNA sequencing of the coding region from amplified genomic DNA from 100 random African Americans. The majority of individuals (97%) carried a KIR2DL1 locus. Allele KIR2DL1*00302 was found in 68% of individuals but KIR2DL1*00401, *002, *00303, *006, and *007 were also frequent. Eleven new alleles were described: KIR2DL1*00403, *01101, *01102, *012, *013N, *014, *015, *016, *017, *018, and *019. Nine of the novel alleles encoded amino acid substitutions located throughout the receptor; one allele carried a stop codon in the exon encoding the first extracellular domain.

Molecular detection of novel adenoviruses in fecal specimens of captive monkeys with diarrhea in China

Adenovirus (AdV) has been recently detected among monkeys with diarrhea in a major research primate colony in China. To better assess disease burden and epidemiology of adenoviruses in the colony, we examined the prevalence of this virus in fecal specimens by PCR using broadly reactive hexon gene-specific primers. Of the 29 strains that were characterized by sequence and phylogenetic analysis, we identified a broad spectrum of simian AdV (SAdV) types, including species SAdV-A (n=14) and HAdV-G (n=9). Six additional strains represented two genetic clusters distantly related to other known SAdVs. A better understanding of the epidemiology of SAdVs and their potential role in gastroenteritis is critical to the implementation of advanced prevention strategies against AdV infection in captive primates.

Size-dependent effects of tungsten carbide-cobalt particles on oxygen radical production and activation of cell signaling pathways in murine epidermal cells

Hard metal or cemented carbide consists of a mixture of tungsten carbide (WC) (85%) and metallic cobalt (Co) (5-15%). WC-Co is considered to be potentially carcinogenic to humans. However, no comparison of the adverse effects of nano-sized WC-Co particles is available to date. In the present study, we compared the ability of nano- and fine-sized WC-Co particles to form free radicals and propensity to activate the transcription factors, AP-1 and NF-kappaB, along with stimulation of mitogen-activated protein kinase (MAPK) signaling pathways in a mouse epidermal cell line (JB6 P(+)). Our results demonstrated that nano-WC-Co generated a higher level of hydroxyl radicals, induced greater oxidative stress, as evidenced by a decrease of GSH levels, and caused faster JB6 P(+) cell growth/proliferation than observed after exposure of cells to fine WC-Co. In addition, nano-WC-Co activated AP-1 and NF-kappaB more efficiently in JB6(+/+) cells as compared to fine WC-Co. Experiments using AP-1-luciferase reporter transgenic mice confirmed the activation of AP-1 by nano-WC-Co. Nano- and fine-sized WC-Co particles also stimulated MAPKs, including ERKs, p38, and JNKs with significantly higher potency of nano-WC-Co. Finally, co-incubation of the JB6(+/+) cells with N-acetyl-cysteine decreased AP-1 activation and phosphorylation of ERKs, p38 kinase, and JNKs, thus suggesting that oxidative stress is involved in WC-Co-induced toxicity and AP-1 activation.

Rotavirus and coxsackievirus infection activated different profiles of toll-like receptors and chemokines in intestinal epithelial cells

OBJECTIVE

To understand the inflammatory-immune response in intestinal epithelial cells after infection of rotavirus and coxsackievirus B3.

METHODS

We examined by quantitative PCR the expression profiles of genes encoding five toll-like receptors (TLR) and levels of three chemokines in response to rotavirus and coxsackievirus B3 infection in a human intestinal epithelial cell line (HT-29 cells).

RESULTS

We demonstrated that rotavirus induced significantly increased levels of mRNA expression for TLR2, TLR3, TLR7 and TLR8 in HT-29 cells in a time-dependent manner. In contrast, coxsackievirus B3 did not stimulate mRNA expression for TLR3. Rotavirus and coxsackievirus B3 also induced higher levels of mRNA expression for RANTES, IP-10 and IL-8 during the period of infection in a different manner. Finally, significantly elevated levels of RANTES, IP-10 and IL-8 were detected by ELISA in rotavirus-infected cells from 24 to 48 h.

CONCLUSION

Our findings suggest that different patterns of TLRs and chemokines were induced in the initiation and modulation of immune response to rotavirus and coxsackievirus B3 infection.