Ubiquitous atmospheric production of organic acids mediated by cloud droplets.

Atmospheric acidity is increasingly determined by carbon dioxide and organic acids1-3. Among the latter, formic acid facilitates the nucleation of cloud droplets4 and contributes to the acidity of clouds and rainwater1,5. At present, chemistry-climate models greatly underestimate the atmospheric burden of formic acid, because key processes related to its sources and sinks remain poorly understood2,6-9. Here we present atmospheric chamber experiments that show that formaldehyde is efficiently converted to gaseous formic acid via a multiphase pathway that involves its hydrated form, methanediol. In warm cloud droplets, methanediol undergoes fast outgassing but slow dehydration. Using a chemistry-climate model, we estimate that the gas-phase oxidation of methanediol produces up to four times more formic acid than all other known chemical sources combined. Our findings reconcile model predictions and measurements of formic acid abundance. The additional formic acid burden increases atmospheric acidity by reducing the pH of clouds and rainwater by up to 0.3. The diol mechanism presented here probably applies to other aldehydes and may help to explain the high atmospheric levels of other organic acids that affect aerosol growth and cloud evolution.

Staging accuracy of MRI of the prostate with special reference to the influence of the time of last ejaculation on the detection of seminal vesicle invasion.

AIM: To evaluate the Prostate Imaging Reporting and Data System, version 2.1 (PIRADS V2.1) criteria for seminal vesicle invasion (SVI) and examine whether the timing of last ejaculation influences the detection of SVI. MATERIALS AND METHODS: The study population consisted of 68 patients (34 with SVI, 34 without SVI, matching groups by age and prostate volume) who underwent PIRADS V2.1-compliant multiparametric magnetic resonance imaging (MRI; 34 at 1.5 T, 34 at 3 T). Before the examination, the time of last ejaculation (38/68 ≤ 5 days, 30/68 > 5 days) was collected via a questionnaire. The five PIRADS V2.1 criteria for SVI with subsequent overall assessment were evaluated retrospectively by two independent examiners (examiner 1 with >10 years of experience, examiner 2 with 6 months of experience) in a single-blinded fashion for all patients using a questionnaire and a six-point scale (0 = no, 1 = very likely not, 2 = probably not, 3 = possible, 4 = probable, 5 = certain). RESULTS: E1 achieved high specificity (100%) and positive predictive value (PPV; 100%) in the overall assessment, independent of the time of last ejaculation (sensitivity = 76.5%, negative predictive value [NPV] = 81%). The area under the curve (AUC) value was 0.882; for E2, it was 0.765. At ≤5 days, the AUC values of E1 and E2 differed significantly (0.867 versus 0.681, p=0.016), as did the diffusion restriction criterion (0.833 versus 0.681, p=0.028). E1 showed high AUC values independent of time. E2 had better values for all criteria at >5 days than at ≤5 days. There were no significant differences between the examiners in all observations at >5 days. CONCLUSION: The PIRADS V2.1 criteria are well suited for an experienced examiner to detect SVI independent of time point. An inexperienced examiner will benefit from patients being abstinent >5 days prior to MRI.

Prognostic implication of the neoadjuvant rectal score and other biomarkers of clinical outcome in Hong Kong Chinese patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiotherapy.

BACKGROUND: Neoadjuvant chemoradiotherapy is a standard treatment for locally advanced rectal cancer, for which pathological complete response is typically used as a surrogate survival endpoint. Neoadjuvant rectal score is a new biomarker that has been shown to correlate with survival. The main objectives of this study were to investigate factors contributing to pathological complete response, to validate the prognostic significance of neoadjuvant rectal score, and to investigate factors associated with a lower neoadjuvant rectal score in a cohort of Hong Kong Chinese. METHODS: Data of patients with locally advanced rectal cancer who received neoadjuvant chemoradiotherapy from August 2006 to October 2018 were retrieved from hospital records and retrospectively analysed. RESULTS: Of 193 patients who had optimal response to neoadjuvant chemoradiotherapy and surgery, tumour down-staging was the only independent prognostic factor that predicted pathological complete response (P<0.0001). Neoadjuvant rectal score was associated with overall survival (hazard ratio [HR]=1.042, 95% confidence interval [CI]=1.021-1.064; P<0.0001), disease-free survival (HR=1.042, 95% CI=1.022-1.062; P<0.0001), locoregional recurrence-free survival (HR=1.070, 95% CI=1.039-1.102; P<0.0001) and distant recurrence-free survival (HR=1.034, 95% CI=1.012-1.056; P=0.002). Patients who had pathological complete response were associated with a lower neoadjuvant rectal score (P<0.0001), but pathological complete response was not associated with survival. For patients with intermediate neoadjuvant rectal scores, late recurrences beyond 72 months from diagnosis were observed. CONCLUSION: Neoadjuvant rectal score is an independent prognostic marker of survival and disease recurrence in a cohort of Hong Kong Chinese patients who received neoadjuvant chemoradiotherapy for locally advanced rectal cancer.

Experimental and theoretical study on the impact of a nitrate group on the chemistry of alkoxy radicals.

The chemistry of nitrated alkoxy radicals, and its impact on RO2 measurements using the laser induced fluorescence (LIF) technique, is examined by a combined theoretical and experimental study. Quantum chemical and theoretical kinetic calculations show that the decomposition of ß-nitrate-alkoxy radicals is much slower than ß-OH-substituted alkoxy radicals, and that the spontaneous fragmentation of the α-nitrate-alkyl radical product to a carbonyl product + NO2 prevents other ß-substituents from efficiently reducing the energy barrier. The systematic series of calculations is summarized as an update to the structure-activity relationship (SAR) by Vereecken and Peeters (2009), and shows increasing decomposition rates with higher degrees of substitution, as in the series ethene to 2,3-dimethyl-butene, and dominant H-migration for sufficiently large alkoxy radicals such as those formed from 1-pentene or longer alkenes. The slow decomposition allows other reactions to become competitive, including epoxidation in unsaturated nitrate-alkoxy radicals; the decomposition SAR is likewise updated for ß-epoxy substituents. A set of experiments investigating the NO3-initiated oxidation of ethene, propene, cis-2-butene, 2,3-dimethyl-butene, 1-pentene, and trans-2-hexene, were performed in the atmospheric simulation chamber SAPHIR with measurements of HO2 and RO2 radicals performed with a LIF instrument. Comparisons between modelled and measured HO2 radicals in all experiments, performed in excess of carbon monoxide to avoid OH radical chemistry, suggest that the reaction of HO2 with ß-nitrate alkylperoxy radicals has a channel forming OH and an alkoxy radical in yields of 15-65%, compatible with earlier literature data on nitrated isoprene and α-pinene radicals. Model concentrations of RO2 radicals when including the results of the theoretical calculations described here, agreed within 10% with the measured RO2 radicals for all species investigated when the alkene oxidation is dominated by NO3 radicals. The formation of NO2 in the decomposition of ß-nitrate alkoxy radicals prevents detection of the parent RO2 radical in a LIF instrument, as it relies on formation of HO2. The implications for measurements of RO2 in ambient and experimental conditions, such as for the NO3-dominated chemistry during nighttime, is discussed. The current results appear in disagreement with an earlier indirect experimental study by Yeh et al. on pentadecene.

Theoretical and experimental study of peroxy and alkoxy radicals in the NO3-initiated oxidation of isoprene.

The initial stages of the nitrate radical (NO3) initiated oxidation of isoprene, in particular the fate of the peroxy (RO2) and alkoxy (RO) radicals, are examined by an extensive set of quantum chemical and theoretical kinetic calculations. It is shown that the oxidation mechanism is highly complex, and bears similarities to its OH-initiated oxidation mechanism as studied intensively over the last decade. The nascent nitrated RO2 radicals can interconvert by successive O2 addition/elimination reactions, and potentially have access to a wide range of unimolecular reactions with rate coefficients as high as 35 s-1; the contribution of this chemistry could not be ascertained experimentally. The chemistry of the alkoxy radicals derived from these peroxy radicals is affected by the nitrate moiety, and can lead to the formation of nitrated epoxy peroxy radicals in competition with isomerisation and decomposition channels that terminate the organic radical chain by NO2 elimination. The theoretical predictions are implemented in the FZJ-NO3-isoprene mechanism for NO3-initiated atmospheric oxidation of isoprene. The model predictions are compared against peroxy radical (RO2) and methyl vinyl ketone (MVK) measurements in a set of experiments on the isoprene + NO3 reaction system performed in the SAPHIR environmental chamber (IsopNO3 campaign). It is shown that the formation of NO2 from the peroxy radicals can prevent a large fraction of the peroxy radicals from being measured by the laser-induced fluorescence (ROxLIF) technique that relies on a quantitative conversion of peroxy radicals to hydroxyl radicals. Accounting for the relative conversion efficiency of RO2 species in the experiments, the agreement between observations and the theory-based FZJ-NO3-isoprene model predictions improves significantly. In addition, MVK formation in the NO3-initiated oxidation was found to be suppressed by the epoxidation of the unsaturated RO radical intermediates, allowing the model-predicted MVK concentrations to be in good agreement with the measurements. The FZJ-NO3-isoprene mechanism is compared against the MCM v3.3.1 and Wennberg et al. (2018) mechanisms.

Phthalyl starch nanoparticles as prebiotics enhanced nisin production in Lactococcus lactis through the induction of mild stress in probiotics.

AIM OF THE STUDY: Effect of internalized phthalyl starch nanoparticles (PSNs) on the antimicrobial ability of Lactococcus lactis (LL) KCTC 2013. METHODS AND RESULTS: Phthalyl starch nanoparticles were prepared by self-assembly of phthalyl starch and the amount of the hydrophobic phthalic moieties were characterized by nuclear magnetic resonance: PSN1 (DS: 14·3 mol.%), PSN2 (DS: 17·8 mol.%) and PSN3 (DS: 30·4 mol.%). The sizes of PSN1, PSN2 and PSN3 measured by dynamic light scattering were 364·7, 248·4 and 213·4 nm, respectively, and the surface charges of PSNs measured by electrophoretic light scattering were negative charges and PSNs were spherical in shape according to scanning electron microscope. It was found that when PSNs were treated with LL, the PSNs were internalized into LL through nanoparticle size-, energy- and glucose transporter-dependent mechanisms. The internalization was confirmed by confocal laser scanning microscopy and fluorescence-activated cell sorting. Nisin was isolated and identified by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Also, more nisin was produced from PSNs-treated LL than untreated- or starch-treated LL. Co-culture assay and agar diffusion test were performed to test the antimicrobial ability. Antimicrobial ability against Gram-negative Escherichia coli k88, Salmonella gallinarum and Gram-positive Listeria monocytogenes of LL treated with PSNs was higher than that of untreated or starch-treated group. Finally, it was found that the expression level of stress response genes dnaK, dnaJ and groES was significantly higher in PSNs-treated groups compared with starch-treated group or LL alone. CONCLUSION: The internalization of PSNs into LL enhanced the production of nisin through mild intracellular stimulation, resulting in enhanced antimicrobial ability. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows the promising potential of PSNs as new prebiotics for increasing the production of nisin, thus demonstrating a new method for the biological production of such antimicrobial peptides.

Helicobacter pylori seropositivity is associated with antinuclear antibodies in US adults, NHANES 1999-2000.

Infectious diseases, such as Helicobacter pylori, which produce systemic inflammation may be one key factor in the onset of autoimmunity. The association between H. pylori and antinuclear antibodies (ANA), a marker of autoimmunity, has been understudied. Data from the 1999-2000 National Health and Nutrition Examination Survey were used to evaluate the cross-sectional association between H. pylori seroprevalence and ANA positivity in US adults aged ≥20 years. ANA was measured in a 1:80 dilution of sera by indirect immunofluorescence using HEp-2 cells (positive ⩾3). H. pylori immunoglobulin G enzyme-linked immunosorbent assays were used to categorise individuals as seropositive or seronegative. H. pylori seropositivity and ANA positivity were common in the adult US population, with estimated prevalences of 33.3% and 9.9%, respectively. Both were associated with increasing age. H. pylori seropositivity was associated with higher odds of ANA (prevalence odds ratio = 1.89, 95% confidence interval = 1.08-3.33), adjusted for age, sex, race/ethnicity, educational attainment and body mass index. H. pylori infection may be one key factor in the loss of self-tolerance, contributing to immune dysfunction.

Efficacy, Immunogenicity, and Safety of a 9-Valent Human Papillomavirus Vaccine: Subgroup Analysis of Participants From Asian Countries.

Background: A 9-valent human papillomavirus-6/11/16/18/31/33/45/52/58 (9vHPV) vaccine extends coverage to 5 next most common oncogenic types (31/33/45/52/58) in cervical cancer versus quadrivalent HPV (qHPV) vaccine. We describe efficacy, immunogenicity, and safety in Asian participants (India, Hong Kong, South Korea, Japan, Taiwan, and Thailand) from 2 international studies: a randomized, double-blinded, qHPV vaccine-controlled efficacy study (young women aged 16-26 years; NCT00543543; Study 001); and an immunogenicity study (girls and boys aged 9-15 years; NCT00943722; Study 002). Methods: Participants (N = 2519) were vaccinated at day 1 and months 2 and 6. Gynecological samples (Study 001 only) and serum were collected for HPV DNA and antibody assessments, respectively. Injection-site and systemic adverse events (AEs) were monitored. Data were analyzed by country and vaccination group. Results: 9vHPV vaccine prevented HPV-31/33/45/52/58-related persistent infection with 90.4%-100% efficacy across included countries. At month 7, ≥97.9% of participants seroconverted for each HPV type. Injection-site AEs occurred in 77.7%-83.1% and 81.9%-87.5% of qHPV and 9vHPV vaccine recipients in Study 001, respectively, and 62.4%-85.7% of girls/boys in Study 002; most were mild to moderate. Conclusions: The 9vHPV vaccine is efficacious, immunogenic, and well tolerated in Asian participants. Data support 9vHPV vaccination programs in Asia. Clinical Trials Registration: NCT00543543; NCT00943722.

Fungal Planet description sheets: 716-784.

Novel species of fungi described in this study include those from various countries as follows: Australia, Chaetopsina eucalypti on Eucalyptus leaf litter, Colletotrichum cobbittiense from Cordyline stricta × C. australis hybrid, Cyanodermella banksiae on Banksia ericifolia subsp. macrantha, Discosia macrozamiae on Macrozamia miquelii, Elsinoë banksiigena on Banksia marginata, Elsinoë elaeocarpi on Elaeocarpus sp., Elsinoë leucopogonis on Leucopogon sp., Helminthosporium livistonae on Livistona australis, Idriellomyces eucalypti (incl. Idriellomyces gen. nov.) on Eucalyptus obliqua, Lareunionomyces eucalypti on Eucalyptus sp., Myrotheciomyces corymbiae (incl. Myrotheciomyces gen. nov., Myrotheciomycetaceae fam. nov.), Neolauriomyces eucalypti (incl. Neolauriomyces gen. nov., Neolauriomycetaceae fam. nov.) on Eucalyptus sp., Nullicamyces eucalypti (incl. Nullicamyces gen. nov.) on Eucalyptus leaf litter, Oidiodendron eucalypti on Eucalyptus maidenii, Paracladophialophora cyperacearum (incl. Paracladophialophoraceae fam. nov.) and Periconia cyperacearum on leaves of Cyperaceae, Porodiplodia livistonae (incl. Porodiplodia gen. nov., Porodiplodiaceae fam. nov.) on Livistona australis, Sporidesmium melaleucae (incl. Sporidesmiales ord. nov.) on Melaleuca sp., Teratosphaeria sieberi on Eucalyptus sieberi, Thecaphora australiensis in capsules of a variant of Oxalis exilis. Brazil, Aspergillus serratalhadensis from soil, Diaporthe pseudoinconspicua from Poincianella pyramidalis, Fomitiporella pertenuis on dead wood, Geastrum magnosporum on soil, Marquesius aquaticus (incl. Marquesius gen. nov.) from submerged decaying twig and leaves of unidentified plant, Mastigosporella pigmentata from leaves of Qualea parviflorae, Mucor souzae from soil, Mycocalia aquaphila on decaying wood from tidal detritus, Preussia citrullina as endophyte from leaves of Citrullus lanatus, Queiroziella brasiliensis (incl. Queiroziella gen. nov.) as epiphytic yeast on leaves of Portea leptantha, Quixadomyces cearensis (incl. Quixadomyces gen. nov.) on decaying bark, Xylophallus clavatus on rotten wood. Canada, Didymella cari on Carum carvi and Coriandrum sativum. Chile, Araucasphaeria foliorum (incl. Araucasphaeria gen. nov.) on Araucaria araucana, Aspergillus tumidus from soil, Lomentospora valparaisensis from soil. Colombia, Corynespora pseudocassiicola on Byrsonima sp., Eucalyptostroma eucalyptorum on Eucalyptus pellita, Neometulocladosporiella eucalypti (incl. Neometulocladosporiella gen. nov.) on Eucalyptus grandis × urophylla, Tracylla eucalypti (incl. Tracyllaceae fam. nov., Tracyllalales ord. nov.) on Eucalyptus urophylla. Cyprus, Gyromitra anthracobia (incl. Gyromitra subg. Pseudoverpa) on burned soil. Czech Republic, Lecanicillium restrictum from the surface of the wooden barrel, Lecanicillium testudineum from scales of Trachemys scripta elegans. Ecuador, Entoloma yanacolor and Saproamanita quitensis on soil. France, Lentithecium carbonneanum from submerged decorticated Populus branch. Hungary, Pleuromyces hungaricus (incl. Pleuromyces gen. nov.) from a large Fagus sylvatica log. Iran, Zymoseptoria crescenta on Aegilops triuncialis. Malaysia, Ochroconis musicola on Musa sp. Mexico, Cladosporium michoacanense from soil. New Zealand , Acrodontium metrosideri on Metrosideros excelsa, Polynema podocarpi on Podocarpus totara, Pseudoarthrographis phlogis (incl. Pseudoarthrographis gen. nov.) on Phlox subulata. Nigeria, Coprinopsis afrocinerea on soil. Pakistan, Russula mansehraensis on soil under Pinus roxburghii. Russia, Baorangia alexandri on soil in deciduous forests with Quercus mongolica. South Africa, Didymocyrtis brachylaenae on Brachylaena discolor. Spain, Alfaria dactylis from fruit of Phoenix dactylifera, Dothiora infuscans from a blackened wall, Exophiala nidicola from the nest of an unidentified bird, Matsushimaea monilioides from soil, Terfezia morenoi on soil. United Arab Emirates, Tirmania honrubiae on soil. USA, Arxotrichum wyomingense (incl. Arxotrichum gen. nov.) from soil, Hongkongmyces snookiorum from submerged detritus from a fresh water fen, Leratiomyces tesquorum from soil, Talaromyces tabacinus on leaves of Nicotiana tabacum. Vietnam, Afroboletus vietnamensis on soil in an evergreen tropical forest, Colletotrichum condaoense from Ipomoea pes-caprae. Morphological and culture characteristics along with DNA barcodes are provided.

Modelling end-pumped passively Q-switched Nd-doped crystal lasers: manifestation by a Nd:YVO4/Cr4+:YAG system with a concave-convex resonator.

A theoretical model for the passively Q-switched (PQS) operation which includes the spatial overlapping between the pump and lasing modes under the thermal lensing effect is developed to give a transcendental equation that can directly determine the critical parameters such as pulse energy, pulse repetition rate, and pulse width for the PQS performance. More importantly, an analytical function which gives the approximate solution for the transcendental equation as well as a specific critical criterion for good PQS operation are derived for practical analyses and design. A Nd:YVO4/Cr4+:YAG system with a concave-convex resonator which can achieve fairly stable PQS pulse trains even at a high pump level is further exploited to manifest the proposed spatially dependent model. The good agreement between the experimental results and the theoretical predictions is verified to show the feasibility of the proposed model for designing high-power PQS lasers with high accuracy.

Association between antiphospholipid antibodies and arterial thrombosis in patients with rheumatoid arthritis.

OBJECTIVES: Antiphospholipid antibodies (aPL) are present in a proportion of patients with rheumatoid arthritis but their clinical significance remains unclear. We investigated the association between aPL and thrombotic events in rheumatoid arthritis patients. METHODS: In this cross-sectional study, aPL profiles were evaluated in 376 rheumatoid arthritis patients in accordance with the standard guidelines. Clinical and radiographic data were retrospectively collected. RESULTS: aPL were identified in 39 patients (10.4%). Lupus anticoagulant was the most common subtype (n = 25, 6.6%); anti-cardiolipin antibodies and anti-ß2 glycoprotein I antibodies were detected in six and 12 patients (1.6% and 3.2%), respectively. Compared to the aPL-negative group, aPL-positive patients included more male patients (41.0% vs. 15.4%, P < 0.001) and more smokers (41.0% vs. 16.0%, P = 0.001). There was no difference between the two groups in age, disease duration and body mass index, or the frequency of diabetes, hypertension or dyslipidaemia. Of note, arterial thromboses were more common in the aPL-positive than the aPL-negative group (12.8% vs. 2.1%, P = 0.004), whereas the frequency of venous thrombosis did not differ between the two groups (0.0% vs. 0.9%, P = 1.000). On multivariate regression analysis, aPL, age, hypertension, dyslipidaemia and baseline C-reactive protein level were independently associated with arterial thrombotic events (all P values < 0.05). CONCLUSION: aPL was found in a subset of rheumatoid arthritis patients, who were more often smokers, and aPL was independently associated with development of arterial thrombosis. This result suggests that aPL may contribute to an increased risk of arterial thrombosis in rheumatoid arthritis patients.

Systemic therapy in incurable gastroenteropancreatic neuroendocrine tumours: a clinical practice guideline.

PURPOSE: The purpose of the present review was to determine which antineoplastic systemic therapy is most effective in improving clinical outcomes for patients with incurable gastroenteropancreatic neuroendocrine tumours (nets). METHODS: A systematic search (2008-2016) of the literature in the medline and embase databases and the Cochrane Database of Systematic Reviews was conducted; abstracts from the American Society of Clinical Oncology, the American Society of Clinical Oncology Gastrointestinal Cancers Symposium, the European Society for Medical Oncology, the European Cancer Congress, the European Neuroendocrine Tumor Society, and the North American Neuroendocrine Tumor Society were reviewed. Draft recommendations were created, and a comprehensive review process was undertaken. Outcomes-including progression-free survival (pfs), overall survival, objective response rate, adverse events, and quality of life-were extracted from each of the studies. RESULTS: Eleven randomized controlled trials (rcts), sixteen nonrandomized prospective studies, and thirteen retrospective studies met the inclusion criteria. CONCLUSIONS: Patients with well-or moderately-differentiated pancreatic nets (pnets) should receive targeted therapy (that is, everolimus or sunitinib), and patients with non-pnets should be offered either targeted therapy (that is, everolimus) or somatostatin analogues (ssas-that is, octreotide long-acting release or lanreotide). Evidence from two phase iii trials demonstrated a significant pfs benefit for patients with pnets. For patients with non-pnets, the evidence comes from subgroup analyses of rcts, as well as from a planned interim analysis. Although the evidence has limitations, the rarity of the disease, coupled with the difficulty of conducting methodologically sound trials in the affected population, means that treatment decisions have to make use of the best available evidence. Because of insufficient evidence for both pnets and non-pnets, no evidence-based recommendation can be made for or against other types of targeted therapy, other ssas, chemotherapy, or combination therapy.

Analysis of the optimal temperature for the cryogenic monolithic Nd:YAG laser at 946-nm.

The optimal temperature for the cryogenic monolithic Nd:YAG laser at 946-nm is theoretically and experimentally analyzed. It is clear that decreasing temperature can considerably eliminate the thermal population at the lower laser level to enhance the quantum efficiency. However, the narrowing of the absorption bandwidth for the gain medium leads to a reduction of the effective absorption efficiency as the temperature is decreased. Consequently, an optimal temperature for the maximum output power is found to be in the range of approximately 120 K to 140 K. It is experimentally verified that employing a pump source with a narrower emission spectrum linewidth contributes a more efficient output for the cryogenic laser.

Exploiting concave-convex linear resonators to design end-pumped solid-state lasers with flexible cavity lengths: Application for exploring the self-mode-locked operation.

The characteristics of a convex-concave linear resonator under the thermal lensing effect are theoretically analyzed to find an analytical model for designing end-pumped solid-state lasers with flexible cavity lengths. By exploiting the design model, the power scaling for continuous-wave operation under strong thermal lensing can be easily achieved in the proposed resonator with different cavity lengths. Furthermore, the proposed resonator is applied to explore the exclusive influence of cavity length on the self-mode-locked (SML) operation. It is discovered that the lasing longitudinal modes will split into multiple groups in optical spectrum to lead to a multi-pulse mode-locked temporal state when the cavity length increases. Finally, a theoretical model is derived to reconstruct the experimental results of SML operation to deduce a simple relationship between the group number of lasing modes and the cavity length.

Monolithic dual-polarization self-mode-locked Nd:YAG 946-nm lasers: controlling beat frequency and observation of temporal chaos.

The self-mode-locked (SML) operation at 946 nm can be achieved with a monolithic Nd:YAG crystal when the pump power is above the threshold of the multiple-longitudinal-mode generation. The SML output is further found to include two orthogonal polarization components with a beat frequency coming from the birefringence effect in the laser crystal. The beat frequency can be widely adjusted in the range of 5-220 MHz by controlling the cooling temperature. The present experiment also confirms the theoretical prediction that the two-mode operation generally exhibits the chaotic dynamics when the frequency difference is sufficiently close to the relaxation frequency.

Synchronized self-mode-locked 1061-nm and 1064-nm monolithic Nd:YAG laser at cryogenic temperatures with two orthogonally polarized emissions: generation of 670 GHz beating.

A dual-wavelength self-mode-locked monolithic Nd:YAG laser at 1061 and 1064 nm is realized at cryogenic temperatures. At an incident pump power of 5.5 W, the total output power can reach 2.5 W and the mode-locked pulse width is 29 ps at a pulse repetition rate of 7.75 GHz. The synchronization of the dual-wavelength emissions leads to a beat frequency of 670 GHz in the individual mode-locked pulse. It is further discovered that the laser output consists of two orthogonally polarized components with a central frequency difference of 127 MHz. The central frequency difference between two orthogonal polarizations mainly arises from the external mechanical stress introduced by the copper holder for the laser crystal.

Generation of orthogonally polarized self-mode-locked Nd:YAG lasers with tunable beat frequencies from the thermally induced birefringence.

The simultaneous self-mode-locking of two orthogonally polarized states in a Nd:YAG laser is demonstrated by using a short linear cavity. A total output power of 3.8 W can be obtained at an incident pump power of 8.2 W. The beat frequency Δfc between two orthogonally polarized mode-locked components is observed and measured precisely. It is found that the beat frequency increases linearly with an increase in the absorbed pump power. The origin of the beat frequency can be utterly manifested by considering the thermally induced birefringence in the Nd:YAG crystal. The present result offers a promising approach to generate orthogonally polarized mode-locked lasers with tunable beat frequency.

The effects of thermal softening of double-lumen endobronchial tubes on postoperative sore throat, hoarseness and vocal cord injuries: a prospective double-blind randomized trial.

BACKGROUND: It is well known that thermal softening of polyvinyl chloride tracheal tubes reduces nasal damage during nasotracheal intubation. We hypothesized that thermal softening of double-lumen endobronchial tubes (DLTs) may be effective for reducing airway injury. This randomized double-blind study was performed to investigate whether thermal softening of DLTs decreased postoperative sore throat, hoarseness or vocal cord injuries. METHODS: Patients (n=140) undergoing one lung anaesthesia were randomized into two groups (n=70 each) depending on whether the DLT was softened by warming or not before tracheal intubation. The DLTs were placed in warm saline [40(1)°C] in the thermal softening group or in room temperature saline in the control group for 10 min. The vocal cords were examined by using flexible laryngoscopy immediately after extubation. Sore throat and hoarseness were evaluated for three postoperative days. The primary outcomes were the incidence of sore throat, hoarseness, and vocal cord injuries. RESULTS: Sore throat and vocal cord injuries occurred less frequently in the thermal softening group than in the control group [14/70 vs 27/70, risk ratio (95% CI): 0.52 (0.30-0.90), P=0.025 for sore throat; 15/70 vs 27/70, risk ratio (95% CI): 0.56 (0.32-0.95), P=0.042 for vocal cord injuries]. However, the incidence of hoarseness was comparable between the two groups. CONCLUSION: Tracheal intubation with DLTs softened by warming decreased the postoperative incidence of sore throat and vocal cord injuries. Therefore, thermal softening of DLTs before intubation seems to be helpful in reducing airway injuries associated with DLT intubation. CLINICAL TRIAL REGISTRATION: NCT 01626365.

Prevalence and risk factors of chronic rhinosinusitis in South Korea according to diagnostic criteria.

BACKGROUND: We aimed to compare the prevalence and risk factors of chronic rhinosinusitis (CRS) using two different diagnostic criteria with the same statistical data from the Korean National Health and Nutrition Examination Survey in 2009. METHODS: Symptom-based CRS was defined as CRS diagnosed by questionnaires related to nasal symptoms. Endoscopy-based CRS was defined based on endoscopic findings and nasal symptoms of symptom-based CRS. RESULTS: The overall prevalence of CRS based on the different diagnostic criteria was as follows: symptom-based CRS was 10.78% (797 of 7,394) and endoscopy-based CRS was 1.20% (88 of 7,343). Comparing symptom-based CRS to endoscopy-based CRS showed slight agreement (kappa = 0.183 (0.150-0.216, 95% confidence interval)). Allergic rhinitis was identified as a common risk factor for CRS based on the two diagnostic criteria. CONCLUSIONS: The prevalence and risk factors of CRS were quite different from each other according to the different criteria, even in the same population. Therefore, it would be important to consider what specific diagnostic criteria have been adopted in the studies comparing the prevalence of CRS.