Inhibition of stimulated Raman scattering due to the excitation of stimulated Brillouin scattering

The nonlinear coupling between stimulated Raman scattering (SRS) and stimulated Brillouin scattering (SBS) of intense laser in underdense plasma is studied theoretically and numerically. Based upon the fluid model, their coupling equations are derived, and a threshold condition of plasma density perturbations due to SBS for the inhibition of SRS is given. Particle-in-cell simulations show that this condition can be achieved easily by SBS in the so-called fluid regime with kLλD<0.15, where kL is the Langmuir wave number and λD is the Debye length [Kline et al., Phys. Plasmas 13, 055906 (2006)]. SBS can reduce the saturation level of SRS and the temperature of electrons in both homogeneous and inhomogeneous plasma. Numerical simulations also show that this reduced SRS saturation is retained even if the fluid regime condition mentioned above is violated at a later time due to plasma heating

Identification of the genetic determinants of Salmonella enterica serotype Typhimurium that may regulate the expression of the type 1 fimbriae in response to solid agar and static broth culture conditions

<p>Abstract</p> <p>Background</p> <p>Type 1 fimbriae are the most commonly found fimbrial appendages on the outer membrane of <it>Salmonella enterica </it>serotype Typhimurium. Previous investigations indicate that static broth culture favours <it>S</it>. Typhimurium to produce type 1 fimbriae, while non-fimbriate bacteria are obtained by growth on solid agar media. The phenotypic expression of type 1 fimbriae in <it>S</it>. Typhimurium is the result of the interaction and cooperation of several genes in the <it>fim </it>gene cluster. Other gene products that may also participate in the regulation of type 1 fimbrial expression remain uncharacterized.</p> <p>Results</p> <p>In the present study, transposon insertion mutagenesis was performed on <it>S</it>. Typhimurium to generate a library to screen for those mutants that would exhibit different type 1 fimbrial phenotypes than the parental strain. Eight-two mutants were obtained from 7,239 clones screened using the yeast agglutination test. Forty-four mutants produced type 1 fimbriae on both solid agar and static broth media, while none of the other 38 mutants formed type 1 fimbriae in either culture condition. The flanking sequences of the transposons from 54 mutants were cloned and sequenced. These mutants can be classified according to the functions or putative functions of the open reading frames disrupted by the transposon. Our current results indicate that the genetic determinants such as those involved in the fimbrial biogenesis and regulation, global regulators, transporter proteins, prophage-derived proteins, and enzymes of different functions, to name a few, may play a role in the regulation of type 1 fimbrial expression in response to solid agar and static broth culture conditions. A complementation test revealed that transforming a recombinant plasmid possessing the coding sequence of a NAD(P)H-flavin reductase gene <it>ubiB </it>restored an <it>ubiB </it>mutant to exhibit the type 1 fimbrial phenotype as its parental strain.</p> <p>Conclusion</p> <p>Genetic determinants other than the <it>fim </it>genes may involve in the regulation of type 1 fimbrial expression in <it>S</it>. Typhimurium. How each gene product may influence type 1 fimbrial expression is an interesting research topic which warrants further investigation.</p

Intramuscular electroporation with the pro-opiomelanocortin gene in rat adjuvant arthritis

Endogenous opioid peptides have an essential role in the intrinsic modulation and control of inflammatory pain, which could be therapeutically useful. In this study, we established a muscular electroporation method for the gene transfer of pro-opiomelanocortin (POMC) in vivo and investigated its effect on inflammatory pain in a rat model of rheumatoid arthritis. The gene encoding human POMC was inserted into a modified pCMV plasmid, and 0–200 μg of the plasmid-POMC DNA construct was transferred into the tibialis anterior muscle of rats treated with complete Freund's adjuvant (CFA) with or without POMC gene transfer by the electroporation method. The safety and efficiency of the gene transfer was assessed with the following parameters: thermal hyperalgesia, serum adrenocorticotropic hormone (ACTH) and endorphin levels, paw swelling and muscle endorphin levels at 1, 2 and 3 weeks after electroporation. Serum ACTH and endorphin levels of the group into which the gene encoding POMC had been transferred were increased to about 13–14-fold those of the normal control. These levels peaked 1 week after electroporation and significantly decreased 2 weeks after electroporation. Rats that had received the gene encoding POMC had less thermal hypersensitivity and paw swelling than the non-gene-transferred group at days 3, 5 and 7 after injection with CFA. Our promising results showed that transfer of the gene encoding POMC by electroporation is a new and effective method for its expression in vivo, and the analgesic effects of POMC cDNA with electroporation in a rat model of rheumatoid arthritis are reversed by naloxone

Obliquity pacing of the western Pacific Intertropical Convergence Zone over the past 282,000 years

The Intertropical Convergence Zone (ITCZ) encompasses the heaviest rain belt on the Earth. Few direct long-term records, especially in the Pacific, limit our understanding of long-term natural variability for predicting future ITCZ migration. Here we present a tropical precipitation record from the Southern Hemisphere covering the past 282,000 years, inferred from a marine sedimentary sequence collected off the eastern coast of Papua New Guinea. Unlike the precession paradigm expressed in its East Asian counterpart, our record shows that the western Pacific ITCZ migration was influenced by combined precession and obliquity changes. The obliquity forcing could be primarily delivered by a cross-hemispherical thermal/pressure contrast, resulting from the asymmetric continental configuration between Asia and Australia in a coupled East Asian-Australian circulation system. Our finding suggests that the obliquity forcing may play a more important role in global hydroclimate cycles than previously thought

Reducing the communication complexity with quantum entanglement

We propose a probabilistic two-party communication complexity scenario with a prior nonmaximally entangled state, which results in less communication than that is required with only classical random correlations. A simple all-optical implementation of this protocol is presented and demonstrates our conclusion.Comment: 4 Pages, 2 Figure

Angiogenesis inhibitor therapies for advanced renal cell carcinoma: Toxicity and treatment patterns in clinical practice from a global medical chart review

The aim of this study was to assess the treatment patterns and safety of sunitinib, sorafenib and bevacizumab in real-world clinical settings in US, Europe and Asia. Medical records were abstracted at 18 community oncology clinics in the US and at 21 tertiary oncology centers in US, Europe and Asia for 883 patients ≥18 years who had histologically/cytologically confirmed diagnosis of advanced RCC and received sunitinib (n=631), sorafenib (n=207) or bevacizumab (n=45) as first‑line treatment. No prior treatment was permitted. Data were collected on all adverse events (AEs) and treatment modifications, including discontinuation, interruption and dose reduction. Treatment duration was estimated using Kaplan-Meier analysis. Demographics were similar across treatment groups and regions. Median treatment duration ranged from 6.1 to 10.7 months, 5.1 to 8.5 months and 7.5 to 9.8 months for sunitinib, sorafenib and bevacizumab patients, respectively. Grade 3/4 AEs were experienced by 26.0, 28.0 and 15.6% of sunitinib, sorafenib and bevacizumab patients, respectively. Treatment discontinuations occurred in 62.4 (Asia) to 63.1% (US) sunitinib, 68.8 (Asia) to 90.0% (Europe) sorafenib, and 66.7 (Asia) to 81.8% (US) bevacizumab patients. Globally, treatment modifications due to AEs occurred in 55.1, 54.2 and 50.0% sunitinib, sorafenib and bevacizumab patients, respectively. This study in a large, global cohort of advanced RCC patients found that angiogenesis inhibitors are associated with high rates of AEs and treatment modifications. Findings suggest an unmet need for more tolerable agents for RCC treatment