A Simple and Efficient Centrifugation Filtration Method for Bacterial Concentration and Isolation Prior to Testing Liquid Specimens with Laser-Induced Breakdown Spectroscopy

An inexpensive filtration device was designed and constructed to rapidly concentrate bacteria in a liquid suspension on the surface of a disposable filter medium while at the same time separating the bacterial cells from larger contaminants in the suspension on the basis of their size. The device consists of a two-stage insert that is held rigidly in a standard tube during bacterial suspension centrifugation. The filters can be easily removed from the insert for subsequent testing with laser-induced breakdown spectroscopy in a process that takes only three minutes. Filter media of 0.45 micron pore size was found to capture approximately 90-95% of the cells in suspension. A limit of detection of 90,000 cells per laser shot was calculated by constructing a calibration curve from multiple suspensions of varying concentration. Deposition of the bacterial lawn across the surface of the 9.5 mm diameter filters was found to be uniform to within +/- 20% of the mean as determined by the total measured optical breakdown emission. Use of 5 micron pore size filter media in the first stage of the insert was found to remove close to 100% of a 12 micron grain size tungsten contamination from the suspension while removing 10% of the bacterial cells. This mounting protocol provides a very convenient method for sample preparation that makes use of common techniques, apparatus, and procedures that would be familiar to clinicians or microbiological pathology laboratory personnel

Measurements of total cross sections for positron scattering by uracil molecules

We present measurements of total cross sections for 1 to 30 eV positrons scattered by uracil molecules. The measurements are done using a beam transmission technique on a setup adjusted to accommodate the nature of uracil and we discuss possibilities of future experiments studying positron interactions with more complicated targets. These and future investigations of positron interactions with biomolecules have potential relevance to various biomedical applications

Concentration of Bacterial Specimens During Centrifugation Prior to Laser-Induced Breakdown Spectroscopy Analysis

A metal cone device has been designed and fabricated for use with a custom centrifuge tube insert to allow the simple and rapid concentration of bacterial cells in a circular area with a diameter of 1 mm. The device concentrates cells suspended in up to 1 mL of liquid at the center of a highly flat disposable filter medium which can be easily removed from the centrifuge tube insert for subsequent testing with laser-induced breakdown spectroscopy. Two-dimensional elemental mapping of the filter evidenced a high concentration of bacteria on the filter under the location of the cone hole, as well as detection of reduced bacterial signal in peripheral areas slightly outside the footprint of the cone hole indicating some leakage of bacteria. Nine different dilutions of a suspension of E. coli were prepared and after measurement of the titer by optical densitometry, deposited on the filter media using the cone concentrator. A calibration curve constructed from forty spectra obtained from each of the nine different concentrations returned a LIBS bacterial limit of detection of 10,865 3,712 CFU per laser ablation event for bacteria deposited on filters using the metal cone. Limits of detection calculated using only certain elements observed in the LIBS spectra and present in very low concentrations in the filter were even lower: 1,070 272CFU for magnesium and 1,784 657 CFU for calcium. This represents a factor of 50 reduction in the limit of detection compared to our previously reported value

The first WHO global survey on infection prevention and control in health-care facilities

Background: WHO core components for infection prevention and control (IPC) are important building blocks for effective IPC programmes. To our knowledge, we did the first WHO global survey to assess implementation of these programmes in health-care facilities. Methods: In this cross-sectional survey, IPC professionals were invited through global outreach and national coordinated efforts to complete the online WHO IPC assessment framework (IPCAF). The survey was created in English and was then translated into ten languages: Arabic, Chinese, English, French, German, Italian, Japanese, Russian, Spanish, and Thai. Post-stratification weighting was applied and countries with low response rates were excluded to improve representativeness. Weighted median scores and IQRs as well as weighted proportions (Nw) meeting defined IPCAF minimum requirements were reported. Indicators associated with the IPCAF score were assessed using a generalised estimating equation. Findings: From Jan 16 to Dec 31, 2019, 4440 responses were received from 81 countries. The overall weighted IPCAF median score indicated an advanced level of implementation (605, IQR 450·4–705·0), but significantly lower scores were found in low-income (385, 279·7–442·9) and lower-middle-income countries (500·4, 345·0–657·5), and public facilities (515, 385–637·8). Core component 8 (built environment; 90·0, IQR 75·0–100·0) and core component 2 (guidelines; 87·5, 70·0–97·5) scored the highest, and core component 7 (workload, staffing, and bed occupancy; 70·0, 50–90) and core component 3 (education and training; 70 ·0, 50·0–85·0) scored the lowest. Overall, only 15·2% (Nw: 588 of 3873) of facilities met all IPCAF minimum requirements, ranging from 0% (0 of 417) in low-income countries to 25·6% (278 of 1087) in primary facilities, 9% (24 of 268) in secondary facilities, and 19% (18 of 95) in tertiary facilities in high-income countries. Interpretation: Despite an overall high IPCAF score globally, important gaps in IPC facility implementation and core components across income levels hinder IPC progress. Increased support for more effective and sustainable IPC programmes is crucial to reduce risks posed by outbreaks to global health security and to ensure patient and health worker safety. Funding: WHO and the Infection Control Programme, University of Geneva Hospitals and Faculty of Medicine. Translations: For the French and Spanish translations of the abstract see Supplementary Materials section.Peer Reviewe

Optimized loading of an optical dipole trap for the production of Chromium BECs

We report on a strategy to maximize the number of chromium atoms transferred from a magneto-optical trap into an optical trap through accumulation in metastable states via strong optical pumping. We analyse how the number of atoms in a chromium Bose Einstein condensate can be raised by a proper handling of the metastable state populations. Four laser diodes have been implemented to address the four levels that are populated during the MOT phase. The individual importance of each state is specified. To stabilize two of our laser diode, we have developed a simple ultrastable passive reference cavity whose long term stability is better than 1 MHz

The Interface Region Imaging Spectrograph (IRIS)

The Interface Region Imaging Spectrograph (IRIS) small explorer spacecraft provides simultaneous spectra and images of the photosphere, chromosphere, transition region, and corona with 0.33-0.4 arcsec spatial resolution, 2 s temporal resolution and 1 km/s velocity resolution over a field-of-view of up to 175 arcsec x 175 arcsec. IRIS was launched into a Sun-synchronous orbit on 27 June 2013 using a Pegasus-XL rocket and consists of a 19-cm UV telescope that feeds a slit-based dual-bandpass imaging spectrograph. IRIS obtains spectra in passbands from 1332-1358, 1389-1407 and 2783-2834 Angstrom including bright spectral lines formed in the chromosphere (Mg II h 2803 Angstrom and Mg II k 2796 Angstrom) and transition region (C II 1334/1335 Angstrom and Si IV 1394/1403 Angstrom). Slit-jaw images in four different passbands (C II 1330, Si IV 1400, Mg II k 2796 and Mg II wing 2830 Angstrom) can be taken simultaneously with spectral rasters that sample regions up to 130 arcsec x 175 arcsec at a variety of spatial samplings (from 0.33 arcsec and up). IRIS is sensitive to emission from plasma at temperatures between 5000 K and 10 MK and will advance our understanding of the flow of mass and energy through an interface region, formed by the chromosphere and transition region, between the photosphere and corona. This highly structured and dynamic region not only acts as the conduit of all mass and energy feeding into the corona and solar wind, it also requires an order of magnitude more energy to heat than the corona and solar wind combined. The IRIS investigation includes a strong numerical modeling component based on advanced radiative-MHD codes to facilitate interpretation of observations of this complex region. Approximately eight Gbytes of data (after compression) are acquired by IRIS each day and made available for unrestricted use within a few days of the observation.Comment: 53 pages, 15 figure

Mitoxantrone pleurodesis to palliate malignant pleural effusion secondary to ovarian cancer

BACKGROUND: Advanced ovarian cancer is the leading non-breast gynaecologic cause of malignant pleural effusion. Aim of this study was to assess the efficacy of mitoxantrone sclerotherapy as a palliative treatment of malignant pleural effusions due to ovarian cancer. METHODS: Sixty women with known ovarian cancer and malignant recurrent symptomatic pleural effusion were treated with chest tube drainage followed by intrapleural mitoxantrone sclerotherapy. Survival, complications and response to pleurodesis were recorded. The data are expressed as the mean ± SEM and the median. RESULTS: The mean age of the entire group was 64 ± 11,24 years. The mean interval between diagnosis of ovarian cancer and presentation of the effusion was 10 ± 2,1 months. Eighteen patients (30%) had pleural effusion as the first evidence of recurrence. The mean volume of effusion drained was 1050 ± 105 ml and chest tube was removed within 4 days in 75% of patients. There were no deaths related to the procedure. Side effects of chemical pleurodesis included fever (37–38,5°C) chest pain, nausea and vomiting. At 30 days among 60 treated effusions, there was an 88% overall response rate, including 41 complete responses and 12 partial responses. At 60 days the overall response was 80% (38 complete responses and 10 partial responses). The mean survival of the entire population was 7,5 ± 1,2 months. CONCLUSIONS: Mitoxantrone is effective in the treatment of malignant pleural effusion secondary to ovarian cancer without causing significant local or systemic toxicity

Efficacy and Safety of Tunneled Pleural Catheters in Adults with Malignant Pleural Effusions: A Systematic Review

BackgroundMalignant pleural effusions (MPE) are a frequent cause of dyspnea and discomfort at the end of cancer patients' lives. The tunneled indwelling pleural catheter (TIPC) was approved by the FDA in 1997 and has been investigated as a treatment for MPE.ObjectiveTo systematically review published data on the efficacy and safety of the TIPC for treatment of MPE.DesignWe searched the MEDLINE, EMBASE, and ISI Web of Science databases to identify studies published through October 2009 that reported outcomes in adult patients with MPE treated with a TIPC. Data were aggregated using summary statistics when outcomes were described in the same way among multiple primary studies.Main measuresSymptomatic improvement and complications associated with use of the TIPC.Key resultsNineteen studies with a total of 1,370 patients met criteria for inclusion in the review. Only one randomized study directly compared the TIPC with the current gold standard treatment, pleurodesis. All other studies were case series. Symptomatic improvement was reported in 628/657 patients (95.6%). Quality of life measurements were infrequently reported. Spontaneous pleurodesis occurred in 430/943 patients (45.6%). Serious complications were rare and included empyema in 33/1168 patients (2.8%), pneumothorax requiring a chest tube in 3/51 (5.9%), and unspecified pneumothorax in 17/439 (3.9%). Minor complications included cellulitis in 32/935 (3.4%), obstruction/clogging in 33/895 (3.7%) and unspecified malfunction of the catheter in 11/121 (9.1%). The use of the TIPC was without complication in 517/591 patients (87.5%).ConclusionsBased on low-quality evidence in the form of case series, the TIPC may improve symptoms for patients with MPE and does not appear to be associated with major complications. Prospective randomized studies comparing the TIPC to pleurodesis are needed before the TIPC can be definitively recommended as a first-line treatment of MPE