Influence of grain growth on CO2 ice spectroscopic profiles : Modelling for dense cores and disks

Interstellar dust grain growth in dense clouds and protoplanetary disks, even moderate, affects the observed interstellar ice profiles as soon as a significant fraction of dust grains is in the size range close to the wave vector at the considered wavelength. The continuum baseline correction made prior to analysing ice profiles influences the subsequent analysis and hence the estimated ice composition, typically obtained by band fitting using thin film ice mixture spectra. We model the effect of grain growth on ice mantle spectroscopic profiles, focusing on CO2 to see how it can affect interstellar ice mantle spectral analysis and interpretation. Using the Discrete Dipole Approximation for Scattering and Absorption of Light, the mass absorption coefficients of distributions of grains composed of ellipsoidal silicate cores with water and carbon dioxide ice mantles are calculated. A few other ice mantle compositions are also calculated. We explore the size distribution evolution from dense clouds to simulate the first steps of grain growth up to three microns in size. The results are injected into RADMC-3D full scattering radiative transfer models of spherical clouds and protoplanetary disk templates to retrieve observable spectral energy distributions. We focus on calculated profile of the CO2 antisymmetric stretching mode ice band profile at 4.27 microns, a meaningful indicator of grain growth. The observed profiles toward dense cores with the Infrared space observatory and Akari satellites already showed profiles possibly indicative of moderate grain growth.The observation of protoplanetary disks at high inclination with the JWST should present distorted profiles that will put constraints on the extent of dust growth. The more evolved the dust size distribution, the more the extraction of the ice mantle composition will require both understanding and taking into account grain growth.Comment: 19 pages, 16 figure

Tigecycline is efficacious in the treatment of complicated intra-abdominal infections

Background Empiric treatment of complicated intra-abdominal infections (cIAI) represents a clinical challenge because of the diverse bacteriology and the emergence of bacterial resistance. The efficacy and safety of tigecycline (TGC), a first-in-class, expanded broad-spectrum glycylcycline antibiotic, were compared with imipenem/cilastatin (IMI/CIS) in patients with cIAI. Methods In this prospective, double-blind, phase 3, multinational trial, patients were randomly assigned to intravenous (IV) TGC (100 mg initial dose, then 50 mg every 12 h) or IV IMI/CIS (500/500 mg every 6 h) for 5–14 days. Clinical response was assessed at the test-of-cure (TOC) visit (14–35 days after therapy) for microbiologically evaluable (ME) and microbiologically modified intent-to-treat (m-mITT) populations (co-primary efficacy endpoint populations in which cure/failure response rates were determined). Results Of 817 mITT patients (i.e., received ≥ 1 dose of study drug), 641 (78%) comprised the m-mITT cohort (322 TGC, 319 IMI/CIS) and 523 (64%) were ME (266 TGC, 256 IMI/CIS). Patients were predominantly white (88%) and male (59%) with a mean age of 49 years. The primary diagnoses for the mITT group were complicated appendicitis (41%), cholecystitis (22%), and intra-abdominal abscess (11%). For the ME population, clinical cure rates at TOC were 91.3% (242/265) for TGC versus 89.9% (232/258) for IMI/CIS (95% CI −4.0, 6.8; P < 0.001). Corresponding clinical cure rates within the m-mITT population were 86.6% (279/322) for TGC versus 84.6% (270/319) for IMI/CIS (95% CI −3.7, 7.5; P < 0.001 for noninferiority TGC versus IMI/CIS). The most commonly reported adverse events for TGC and IMI/CIS were nausea (17.6% TGC versus 13.3% IMI/CIS; P = 0.100) and vomiting (12.6% TGC versus 9.2% IMI/CIS; P = 0.144). Conclusions TGC is efficacious in the treatment of patients with cIAIs and TGC met per the protocol-specified statistical criteria for noninferiority to the comparator, IMI/CIS

Which individuals are at increased risk of pneumococcal disease and why? Impact of COPD, asthma, smoking, diabetes, and/or chronic heart disease on community-acquired pneumonia and invasive pneumococcal disease

Pneumococcal disease (including community-acquired pneumonia and invasive pneumococcal disease) poses a burden to the community all year round, especially in those with chronic underlying conditions. Individuals with COPD, asthma or who smoke, and those with chronic heart disease or diabetes mellitus have been shown to be at increased risk of pneumococcal disease compared with those without these risk factors. These conditions, and smoking, can also adversely affect patient outcomes, including short-term and long-term mortality rates, following pneumonia. Community-acquired pneumonia, and in particular pneumococcal pneumonia, is associated with a significant economic burden, especially in those who are hospitalised, and also has an impact on a patient's quality of life. Therefore, physicians should target individuals with COPD, asthma, heart disease or diabetes mellitus, and those who smoke, for pneumococcal vaccination at the earliest opportunity at any time of the year

A retrospective study of hospitalized pneumonia in two Polish counties (2006–2008)

WSTĘP: Dane dotyczące etiologii zapaleń płuc w Polsce są skąpe, a wyszczepialność szczepionką pneumokokową wśród osób w najmłodszej i najstarszej grupie wiekowej — nieznaczna. Celem prezentowanego badania była ocena leczonego szpitalnie zapalenia płuc we wszystkich grupach wiekowych w dwóch powiatach Polski.MATERIAŁ I METODY: W badaniu wykorzystano dane zawarte w elektronicznych szpitalnych bazach danych, dotyczące mieszkańców powiatów, hospitalizowanych w Szpitalach Powiatowych w Chrzanowie i Inowrocławiu w latach 2006–2008, z rozpoznaniem zapalenia płuc. Uzyskane wyniki: częstość hospitalizacji na 1000 osób, współczynnik śmiertelności w trakcie pobytu w szpitalu na 100 osób, mediana długości hospializacji, zgrupowano według roku przyjęcia, płci i wieku.WYNIKI: W Szpitalu Powiatowym w Chrzanowie stwierdzono 1444, a w Inowrocławiu 2956 przypadków hospitalizacji z niezależnymi epizodami zapalenia płuc. Częstość hospitalizacji wyniosła 3,76 (95% przedział ufności [CI]: 3,57;3,96) i 5,99 (95% CI: 5,77; 6,21) na 1000, odpowiednio dla powiatów chrzanowskiego i inowrocławskiego. W całej badanej grupie najwyższą częstość hospitalizacji obserwowano w grupie 0–4 lat (30,77 [95% CI: 29,06; 32,55]) oraz ≥ 75 lat (25,39 [95% CI: 24,01; 26,83]). Współczynnik śmiertelności w szpitalu w obu badanych ośrodkach wzrastał wraz z wiekiem. Mediana długości pobytu w szpitalu wyniosła 8 dni.WNIOSKI: Liczba hospitalizacji z powodu zapalenia płuc była znacząca, szczególnie w najmłodszej i najstarszej grupie wiekowej. Przyszłe działania opieki zdrowotnej skierowane do tych grup wiekowych mogą wpłynąć na zapadalność na zapalenie płuc oraz poprawić wyniki leczenia.INTRODUCTION: In Poland, multi-cause pneumonia is not well characterized, and there is limited pneumococcal vaccination in the youngest and oldest age groups. The goal of this study was to assess hospitalized pneumonia across all age groups in two Polish counties.MATERIAL AND METHODS: Using electronic administrative databases, cases were identified as county residents hospitalized at Chrzanów and Inowrocław County Hospitals from 2006–2008, assigned a diagnosis of pneumonia. Calculations by admission year, sex, and age category were: hospitalization rates per 1000 persons; in-hospital mortality rates per 100 persons; and median length of stay (LOS).RESULTS: There were 1444 and 2956 hospitalizations for new episodes of pneumonia with rates of 3.76 (95% confidence interval [CI] 3.57–3.96) and 5.99 (95% CI 5.77–6.21) per 1000 persons in Chrzanów and Inowrocław counties, respectively. In combined data, the highest hospitalization rate was among patients aged 0–4 years (30.77; 95% CI 29.06–32.55) followed by those aged ≥ 75 years (25.39; 95% CI 24.01–26.83). In-hospital mortality rates increased with age at both sites. The median LOS was 8 days.CONCLUSIONS: Pneumonia hospitalizations were substantial, especially for the youngest and oldest age groups. Future public health interventions aimed at these age groups might improve disease outlook

PDRs4All III: JWST's NIR spectroscopic view of the Orion Bar

(Abridged) We investigate the impact of radiative feedback from massive stars on their natal cloud and focus on the transition from the HII region to the atomic PDR (crossing the ionisation front (IF)), and the subsequent transition to the molecular PDR (crossing the dissociation front (DF)). We use high-resolution near-IR integral field spectroscopic data from NIRSpec on JWST to observe the Orion Bar PDR as part of the PDRs4All JWST Early Release Science Program. The NIRSpec data reveal a forest of lines including, but not limited to, HeI, HI, and CI recombination lines, ionic lines, OI and NI fluorescence lines, Aromatic Infrared Bands (AIBs including aromatic CH, aliphatic CH, and their CD counterparts), CO2 ice, pure rotational and ro-vibrational lines from H2, and ro-vibrational lines HD, CO, and CH+, most of them detected for the first time towards a PDR. Their spatial distribution resolves the H and He ionisation structure in the Huygens region, gives insight into the geometry of the Bar, and confirms the large-scale stratification of PDRs. We observe numerous smaller scale structures whose typical size decreases with distance from Ori C and IR lines from CI, if solely arising from radiative recombination and cascade, reveal very high gas temperatures consistent with the hot irradiated surface of small-scale dense clumps deep inside the PDR. The H2 lines reveal multiple, prominent filaments which exhibit different characteristics. This leaves the impression of a "terraced" transition from the predominantly atomic surface region to the CO-rich molecular zone deeper in. This study showcases the discovery space created by JWST to further our understanding of the impact radiation from young stars has on their natal molecular cloud and proto-planetary disk, which touches on star- and planet formation as well as galaxy evolution.Comment: 52 pages, 30 figures, submitted to A&

PDRs4All II: JWST's NIR and MIR imaging view of the Orion Nebula

The JWST has captured the most detailed and sharpest infrared images ever taken of the inner region of the Orion Nebula, the nearest massive star formation region, and a prototypical highly irradiated dense photo-dissociation region (PDR). We investigate the fundamental interaction of far-ultraviolet photons with molecular clouds. The transitions across the ionization front (IF), dissociation front (DF), and the molecular cloud are studied at high-angular resolution. These transitions are relevant to understanding the effects of radiative feedback from massive stars and the dominant physical and chemical processes that lead to the IR emission that JWST will detect in many Galactic and extragalactic environments. Due to the proximity of the Orion Nebula and the unprecedented angular resolution of JWST, these data reveal that the molecular cloud borders are hyper structured at small angular scales of 0.1-1" (0.0002-0.002 pc or 40-400 au at 414 pc). A diverse set of features are observed such as ridges, waves, globules and photoevaporated protoplanetary disks. At the PDR atomic to molecular transition, several bright features are detected that are associated with the highly irradiated surroundings of the dense molecular condensations and embedded young star. Toward the Orion Bar PDR, a highly sculpted interface is detected with sharp edges and density increases near the IF and DF. This was predicted by previous modeling studies, but the fronts were unresolved in most tracers. A complex, structured, and folded DF surface was traced by the H2 lines. This dataset was used to revisit the commonly adopted 2D PDR structure of the Orion Bar. JWST provides us with a complete view of the PDR, all the way from the PDR edge to the substructured dense region, and this allowed us to determine, in detail, where the emission of the atomic and molecular lines, aromatic bands, and dust originate

Rotationally resolved IR spectroscopy of hexamethylenetetramine (HMT) C₆N₄H₁₂

International audienceHexamethylenetetramine (HMT) appears to be a potential constituent of several objects in space, including comets or Titan's atmosphere and, as an organic residue of ice irradiation in the laboratory, it may be present in the interstellar medium. Aims. We performed a laboratory study of rotationally resolved intense IR bands of HMT to provide accurate line positions and synthetic spectra to be used for potential astronomical detections. Methods. We used synchrotron-based high-resolution Fourier transform infrared spectroscopy to record the experimental data. A formalism and programs dedicated to the assignment, analysis, and simulation of absorption spectra of tetrahedral molecules were used to exploit the spectra. Results. Infrared spectra of gas phase HMT were recorded and accurate wavenumbers and molecular parameters for four intense bands located in the 1000-1500 cm−1 spectral range suitable for astronomical searches were derived

Which individuals are at increased risk of pneumococcal disease and why? Impact of COPD, asthma, smoking, diabetes, and/or chronic heart disease on community-acquired pneumonia and invasive pneumococcal disease

Pneumococcal disease (including community-acquired pneumonia and invasive pneumococcal disease) poses a burden to the community all year round, especially in those with chronic underlying conditions. Individuals with COPD, asthma or who smoke, and those with chronic heart disease or diabetes mellitus have been shown to be at increased risk of pneumococcal disease compared with those without these risk factors. These conditions, and smoking, can also adversely affect patient outcomes, including short-term and long-term mortality rates, following pneumonia. Community-acquired pneumonia, and in particular pneumococcal pneumonia, is associated with a significant economic burden, especially in those who are hospitalised, and also has an impact on a patient's quality of life. Therefore, physicians should target individuals with COPD, asthma, heart disease or diabetes mellitus, and those who smoke, for pneumococcal vaccination at the earliest opportunity at any time of the year