3,672 research outputs found
Abdominal Tuberculosis in Adult: 10-Year Experience in a Teaching Hospital in Central Taiwan
Background/PurposeTuberculosis (TB) is an important communicable disease worldwide. The clinical presentation of abdominal TB often mimics various gastrointestinal disorders and may delay accurate diagnosis. In this study, we conducted a 10-year retrospective study to investigate the clinical manifestations, treatment responses and outcomes of abdominal TB.MethodsThis retrospective study recruited patients presenting between January 1998 and December 2007; all patients ≥ 18 years of age with a diagnosis of abdominal TB were enrolled. Patient charts were thoroughly reviewed and clinical specimens were processed in the laboratory using the BBL MycoPrep System and BACTEC MGIT 960 Mycobacterial Detection System. Mycobacterium tuberculosis complex was confirmed by acid fast stain and the BD ProbeTec ET System.ResultsDuring the study period, 34 patients were diagnosed with abdominal TB. The mean age was 55+18 years. Fourteen patients (41%) had no risk factors; however, 20 patients (59%) had at least one risk factor. Abdominal pain (94.1%), abdominal fullness (91.2%), anorexia (88.2%) and ascites (76.5%) were the most common presenting symptoms. The peritoneum (88%) was the most commonly involved site. Patients with risk factors such as liver cirrhosis, end-stage renal disease and diabetes mellitus had a higher positive rate of acid-fast stain and mycobacterial culture from abdominal specimens (p = 0.02 and 0.05, respectively). The crude mortality rate was 9% and the attributed mortality rate was 3%.ConclusionIn an endemic area like Taiwan, regardless of whether a patient has risk factors for TB, abdominal TB should be seriously considered as a differential diagnosis when a patient presents with gastrointestinal symptoms and unexplained ascites
Near Surface CO2 Triple Oxygen Isotope Composition
The isotopic composition of carbon dioxide in the atmosphere is a powerful tool for constraining its sources and sinks. In particular, the 17O oxygen anomaly [Δ17O = 1000 × ln(1 + δ17O/1000) - 0.516 × 1000 × ln(1 + δ18O/1000)], with a value > 0.5‰ produced in the middle atmosphere, provides an ideal tool for probing the exchange of carbon dioxide between the biosphere/hydrosphere and atmosphere. The biosphere/hydrosphere and anthropogenic emissions give values ≤ 0.3‰. Therefore, any anomaly in near surface CO2 would reflect the balance between stratospheric input and exchange with the aforementioned surface sources. We have analyzed Δ17O values of CO2 separated from air samples collected in Taipei, Taiwan, located in the western Pacific region. The obtained mean anomaly is 0.42 ± 0.14‰ (1-σ standard deviation), in good agreement with model prediction and a published decadal record. Apart from typically used δ13C and δ18O values, the Δ17O value could provide an additional tracer for constraining the carbon cycle
Phase chirality and stereo-selective swelling of cholesteric elastomers
Cholesteric elastomers possess a macroscopic ``phase chirality'' as the
director n rotates in a helical fashion along an optical axis and can be
described by a chiral order parameter. This parameter can be tuned by changing
the helix pitch p and/or the elastic properties of the network. The
cholesterics also possess a local nematic order, changing with temperature or
during solvent swelling. In this paper, by measuring the power of optical
rotation, we discover how these two parameters vary as functions of temperature
or solvent adsorbed by the network. The main result is a finding of pronounced
stereo-selectivity of cholesteric elastomers, demonstrating itself in the
retention of the ``correct'' chirality component of a racemic solvent. It has
been possible to quantify the amount of such stereo-separation, as the basic
dynamics of the effect
Correlation of virulence genes to clinical manifestations and outcome in patients with Streptococcus dysgalactiae subspecies equisimilis bacteremia
Background/PurposeStreptococcus dysgalactiae subsp. equisimilis (SDSE) is increasingly recognized as a human pathogen responsible for invasive infection and streptococcal toxic shock syndrome (STSS). The pathogen possesses virulence genes that resemble those found in Streptococcus pyogenes (GAS). We analyzed the association between these specific toxic genes, clinical presentations, and outcome in patients with SDSE infections.MethodsPatients (older than 18 years) with community-acquired invasive bacteremia caused by SDSE bacteremia who were undergoing treatment at China Medical University Hospital from June 2007 to December 2010 were included in this study. Multiplex polymerase chain reaction was performed to identify virulence genes of the SDSE isolates. Demographic data, clinical presentations, and outcome in patients with SDSE infections were reviewed and analyzed.ResultsForty patients with 41 episodes of SDSE bacteremia were reviewed. The median age of the patients with SDSE infection was 69.7 years; 55% were female and 78% had underlying diseases. Malignancy (13, 33%) and diabetes mellitus (13, 33%) were the most common comorbidities. The 30-day mortality rate was 12%. Compared with the survivors, the non-survivors had a higher rate of diabetes mellitus (80% vs. 26%), liver cirrhosis (60% vs.11%), shock (60% vs.17%), STSS (60% vs. 8%), and a high Pittsburgh bacteremia score >4 (40% vs. 6%). Most isolates had scpA, ska, saga, and slo genes, whereas speC, speG, speH, speI, speK, smez, and ssa genes were not detected. speA gene was identified only in one patient with STSS (1/6, 17%). All isolates were susceptible to penicillin, cefotaxime, levofloxacin, moxifloxacin, vancomycin, and linezolid.ConclusionIn invasive SDSE infections, most isolates carry putative virulence genes, such as scpA, ska, saga, and slo. Clinical SDSE isolates in Taiwan remain susceptible to penicillin cefotaxime, and levofloxacin
Molecular typing of Mycobacterium tuberculosis isolated from adult patients with tubercular spondylitis
Background/PurposeTuberculosis (TB) is endemic in Taiwan and usually affects the lung, spinal TB accounting for 1–3% of all TB infections. The manifestations of spinal TB are different from those of pulmonary TB. The purpose of this study was to define the epidemiological molecular types of mycobacterial strains causing spinal TB.MethodsWe retrospectively reviewed the medical charts of adult patients diagnosed with spinal TB from January 1998 to December 2007. Patients with positive culture results and/or pathological findings characteristic of TB were enrolled in this study. Spoligotyping was performed to type the Mycobacterium tuberculosis isolates.ResultsA total of 38 patients with spinal TB were identified. Their mean age was 68 years, and their median duration of symptoms was 60 days (range 3–720 days). The lumbar and thoracic spine accounted for 76% of the sites involved. Thirteen specimens (from seven male and six female patients) were available for typing. Spoligotyping of these 13 specimens revealed three Beijing (23%) and 10 non-Beijing types (77%). The non-Beijing types included two EAI2 Manilla (15%), two H3 (15%), two unclassified (15%), and one each of BOVIS1, U, T2, and orphan type. No significant predominant strain was found in this study, and no drug-resistant Beijing strains were identified.ConclusionTB spondylitis was found to occur in older patients. Spoligotyping results showed that most of the TB spondylitis cases were caused by non-Beijing type Mycobacterium tuberculosis
Variations in triple isotope composition of dissolved oxygen and primary production in a subtropical reservoir
The work was supported in part by MOST grants 101-2628-M-001-001-MY4 and 105-2111-M-001-006-MY3 to Academia Sinica.Lakes and reservoirs play an important role in the carbon cycle, and therefore monitoring their metabolic rates is essential. The triple oxygen-isotope anomaly of dissolved O2 [17Δ = ln(1+δ17O) − 0.518 × ln(1 + δ18O)] offers a new, in situ, perspective on primary production, yet little is known about 17Δ from freshwater systems. We investigated the 17Δ together with the oxygen : argon ratio [Δ(O2 ∕ Ar)] in the subtropical Feitsui Reservoir in Taiwan from June 2014 to July 2015. Here, we present the seasonal variations in 17Δ, GP (gross production), NP (net production) and the NP ∕ GP (net to gross ratio) in association with environmental parameters. The 17Δ varied with depth and season, with values ranging between 26 and 205 per meg. The GP rates were observed to be higher (702 ± 107 mg C m−2 d−1) in winter than those (303 ± 66 mg C m−2 d−1) recorded during the summer. The overall averaged GP was 220 g C m−2 yr−1 and NP was −3 g C m−2 yr−1, implying the reservoir was net heterotrophic on an annual basis. This is due to negative NP rates from October to February (−198 ± 78 mg C m−2 d−1). Comparisons between GP rates obtained from the isotope mass balance approach and 14C bottle incubation method (14C–GP) showed consistent values on the same order of magnitude with a GP ∕ 14C–GP ratio of 1.2 ± 1.1. Finally we noted that, although typhoon occurrences were scarce, higher than average 17Δ values and GP rates were recorded after typhoon events.Publisher PDFPeer reviewe
Synthesis of Sea Urchin-Like NiCo2O4 via Charge-Driven Self-Assembly Strategy for High Performance Lithium-Ion Batteries
In this study, hydrothermal synthesis of sea urchin-like NiCo2O4 was successfully demonstrated by a versatile charge-driven self-assembly strategy using positively charged poly(diallydimethylammonium chloride) (PDDA) molecules. Physical characterizations implied that sea urchin-like microspheres of ~ 2.5 μm in size were formed by self-assembly of numerous nanoneedles with a typical dimension of ~ 100 nm in diameter. Electrochemical performance study confirmed that sea urchin-like NiCo2O4 exhibited high reversible capacity of 663 mAh g−1 after 100 cycles at current density of 100 mA g−1. Rate capability indicated that average capacities of 1085, 1048, 926, 642, 261, and 86 mAh g−1 could be achieved at 100, 200, 500, 1000, 2000, and 3000 mA g−1, respectively. The excellent electrochemical performances were ascribed to the unique micro/nanostructure of sea urchin-like NiCo2O4, tailored by positively charged PDDA molecules. The proposed strategy has great potentials in the development of binary transition metal oxides with micro/nanostructures for electrochemical energy storage applications
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