A new measurement of the reactor antineutrino flux and energy spectrum by the Daya Bay reactor neutrino experiment is reported. The antineutrinos were generated by six 2.9 GWth nuclear reactors and ...detected by eight antineutrino detectors deployed in two near（560 m and 600 m flux-weighted baselines） and one far（1640 m flux-weighted baseline） underground experimental halls. With 621 days of data, more than 1.2 million inverse beta decay（IBD） candidates were detected. The IBD yield in the eight detectors was measured, and the ratio of measured to predicted flux was found to be 0.946±0.020（0.992±0.021） for the Huber＋Mueller（ILL＋Vogel） model. A 2.9σ deviation was found in the measured IBD positron energy spectrum compared to the predictions. In particular, an excess of events in the region of 4–6 MeV was found in the measured spectrum, with a local significance of 4.4σ. A reactor antineutrino spectrum weighted by the IBD cross section is extracted for model-independent predictions.
Use of negative pressure wound therapy with instillation and dwell time (NPWTi-d) can assist with wound bed preparation for successful closure. The authors present their experience using NPWTi-d to ...manage lower extremity wounds in 4 patients and discuss the feasibility of improving cost efficiency.
NPWTi-d involved instillation of normal saline with an 8-to 10 minute dwell time, followed by 3 to 3.5 hours of -125 mm Hg. Therapy continued for 6 to 7 days with dressing changes every 2 to 3 days.
Patients were all male, between the ages of 24 and 83 years old. Wound etiologies included chemical burn, deep tissue laceration, compartment syndrome with hematoma, and diabetic foot osteomyelitis. All wounds required cleansing. Prior to NPWTi-d, surgical debridement and antibiotics were administered as necessary. After NPWTi-d, the wounds exhibited healthy granulation and reduced in size, allowing for discharge to outpatient care. Upon follow-up 2 to 6 months later, no patients experienced wound complications or required readmission to the operating room, potentially saving on time and cost.
In these patients, use of NPWTi-d assisted in cleansing the wound surface and producing a positive healing outcome. Despite higher initial costs of NPWTi-d over standard dressings, a wound management protocol including NPWTi-d may help mitigate expenses incurred by delayed healing.
The disappearance of reactor
ν
¯
e
observed by the Daya Bay experiment is examined in the framework of a model in which the neutrino is described by a wave packet with a relative intrinsic momentum ...dispersion
σ
rel
. Three pairs of nuclear reactors and eight antineutrino detectors, each with good energy resolution, distributed among three experimental halls, supply a high-statistics sample of
ν
¯
e
acquired at nine different baselines. This provides a unique platform to test the effects which arise from the wave packet treatment of neutrino oscillation. The modified survival probability formula was used to fit Daya Bay data, providing the first experimental limits:
2.38
×
10
-
17
<
σ
rel
<
0.23
. Treating the dimensions of the reactor cores and detectors as constraints, the limits are improved:
10
-
14
≲
σ
rel
<
0.23
, and an upper limit of
σ
rel
<
0.20
(which corresponds to
σ
x
≳
10
-
11
cm
) is obtained. All limits correspond to a 95% C.L. Furthermore, the effect due to the wave packet nature of neutrino oscillation is found to be insignificant for reactor antineutrinos detected by the Daya Bay experiment thus ensuring an unbiased measurement of the oscillation parameters
sin
2
2
θ
13
and
Δ
m
32
2
within the plane wave model.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Although proanthocyanidins (PACs) modify dentin, the effectiveness of different PAC sources and the correlation with their specific chemical composition are still unknown. This study describes the ...chemical profiling of natural PAC-rich extracts from 7 plants using ultra high pressure/performance liquid chromatography (UHPLC) to determine the overall composition of these extracts and, in parallel, comprehensively evaluate their effect on dentin properties. The total polyphenol content of the extracts was determined (as gallic acid equivalents) using Folin-Ciocalteau assays. Dentin biomodification was assessed by the modulus of elasticity, mass change, and resistance to enzymatic biodegradation. Extracts with a high polyphenol and PAC content from Vitis vinifera, Theobroma cacao, Camellia sinensis, and Pinus massoniana induced a significant increase in modulus of elasticity and mass. The UHPLC analysis showed the presence of multiple types of polyphenols, ranging from simple phenolic acids to oligomeric PACs and highly condensed tannins. Protective effect against enzymatic degradation was observed for all experimental groups; however, statistically significant differences were observed between plant extracts. The findings provide clear evidence that the dentin bioactivities of PACs are source dependent, resulting from a combination of concentration and specific chemical constitution of the complex PAC mixtures.
This paper describes the design and performance of a 50 liter, two-segment 6Li-loaded liquid scintillator detector that was designed and operated as prototype for the PROSPECT (Precision Reactor ...Oscillation and Spectrum) Experiment. The two-segment detector was constructed according to the design specifications of the experiment. It features low-mass optical separators, an integrated source and optical calibration system, and materials that are compatible with the 6Li-doped scintillator developed by PROSPECT. We demonstrate a high light collection of 850±20 PE/MeV, an energy resolution of σ=4.0±0.2% at 1 MeV, and efficient pulse-shape discrimination of low dE/dx (electronic recoil) and high dE/dx (nuclear recoil) energy depositions. An effective scintillation attenuation length of 85±3 cm is measured in each segment. The 0.1% by mass concentration of 6Li in the scintillator results in a measured neutron capture time of τ=42.8±0.2μs. The long-term stability of the scintillator is also discussed. The detector response meets the criteria necessary for achieving the PROSPECT physics goals and demonstrates features that may find application in fast neutron detection.
The reactions of aqueous ClO2 • and tryptophan (Trp) are investigated by stopped-flow kinetics, and the products are identified by high-performance liquid chromatography (HPLC) coupled with ...electrospray ionization mass spectrometry and by ion chromatography. The rates of ClO2 • loss increase from pH 3 to 5, are essentially constant from pH 5 to 7, and increase from pH 7 to 10. The reactions are first-order in Trp with variable order in ClO2 •. Below pH 5.0, the reactions are second- or mixed-order in ClO2 •, depending on the chlorite concentration. Above pH 5.0, the reactions are first-order in ClO2 • in the absence of added chlorite. At pH 7.0, the Trp reaction with ClO2 • is first-order in each reactant with a second-order rate constant of 3.4 × 104 M−1 s−1 at 25.0 °C. In the proposed mechanism, the initial reaction is a one-electron oxidation to form a tryptophyl radical cation and chlorite ion. The radical cation deprotonates to form a neutral tryptophyl radical that combines rapidly with a second ClO2 • to give an observable, short-lived adduct (k obs = 48 s−1) with proposed C(H)−OClO bonding. This adduct decays to give HOCl in a three-electron oxidation. The overall reaction consumes two ClO2 • per Trp and forms ClO2 − and HOCl. This corresponds to a four-electron oxidation. Decay of the tryptophyl−OClO adduct at pH 6.4 gives five initial products that are observed after 2 min and are separated by HPLC with elution times that vary from 4 to 17 min (with an eluent of 6.3% CH3OH and 0.1% CH3COOH). Each of these products is characterized by mass spectrometry and UV–vis spectroscopy. One initial product with a molecular weight of 236 decays within 47 min to yield the most stable product, N-formylkynurenine (NFK), which also has a molecular weight of 236. Other products also are observed and examined.
Compartment syndrome is a pathologic condition in which a closed anatomical compartment's pressure, most often in the arms and legs, increases to such an extent that the microcirculation of the ...tissues in that compartment is diminished either acutely or subacutely over time. Such vascular compromise, if untreated, may result in tissue necrosis and muscle and nerve damage. If limb tissue damage is severe enough, amputation of the involved extremity may be necessary. Symptoms of compartment syndrome may include severe pain, diminished or non-palpable pulses, paralysis of the involved extremity, and dermatologic sequela. There are two types of compartment syndrome: acute and chronic. The former is considered a surgical emergency in most cases requiring prompt diagnosis and treatment in order to release intracompartmental pressure thus decreasing the chance of significant tissue damage. In this article, the author presents a novel case in which acute compartment syndrome sequela of the lower leg was successfully treated with surgery, negative pressure wound therapy with instillation and dwell utilizing a novel dressing and serial automated suction blister epidermal harvesting and grafting. The outcome was favorable, resulting in complete limb preservation and return to normal function.
Traditional chemotherapies, aimed at DNA replication in rapidly dividing cells, have achieved only limited success in the treatment of carcinomas due largely to their lack of specificity for cells of ...tumorigenic origin. It is important, therefore, to investigate treatment strategies aimed at novel cellular targets that are sufficiently different between normal cells and cancer cells so as to provide a basis for selective tumor cell killing. Delocalized lipophilic cations (DLCs) are concentrated by cells and into mitochondria in response to negative inside transmembrane potentials. The higher plasma and/or mitochondrial membrane potentials of carcinoma cells compared to normal epithelial cells account for the selective accumulation of DLCs in carcinoma mitochondria. Since most DLCs are toxic to mitochondria at high concentrations, their selective accumulation in carcinoma mitochondria and consequent mitochondrial toxicity provide a basis for selective carcinoma cell killing. Several of these compounds have already displayed some degree of efficacy as chemotherapeutic agents in vitro and in vivo. The effectiveness of DLCs can also be enhanced by their use in photochemotherapy or combination drug therapy. Discovery of the biochemical differences that account for the higher membrane potentials in carcinoma cells is expected to lead to the design of new DLCs targeted specifically to those differences, resulting in even greater selectivity and efficacy for tumor cell killing.
High serum concentration of low-density lipoprotein cholesterol (LDL-C) is a major risk factor for coronary heart disease. The efficacy of pantethine treatment on cardiovascular risk markers was ...investigated in a randomized, triple-blinded, placebo-controlled study, in a low to moderate cardiovascular disease (CVD) risk North American population eligible for statin therapy, using the National Cholesterol Education Program (NCEP) guidelines. A total of 32 subjects were randomized to pantethine (600 mg/day from weeks 1 to 8 and 900 mg/day from weeks 9 to 16) or placebo. Compared with placebo, the participants on pantethine showed a significant decrease in total cholesterol at 16 weeks (P=0.040) and LDL-C at 8 and 16 weeks (P=0.020 and P=0.006, respectively), and decreasing trends in non-high-density lipoprotein cholesterol at week 8 and week 12 (P=0.102 and P=0.145, respectively) that reached significance by week 16 (P=0.042). An 11% decrease in LDL-C from baseline was seen in participants on pantethine, at weeks 4, 8, 12, and 16, while participants on placebo showed a 3% increase at week 16. This decrease was significant between groups at weeks 8 (P=0.027) and 16 (P=0.010). The homocysteine levels for both groups did not change significantly from baseline to week 16. Coenzyme Q10 significantly increased from baseline to week 4 and remained elevated until week 16, in both the pantethine and placebo groups. After 16 weeks, the participants on placebo did not show significant improvement in any CVD risk end points. This study confirms that pantethine lowers cardiovascular risk markers in low to moderate CVD risk participants eligible for statins according to NCEP guidelines.
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