With the growing needs for flexible fluorescence emission materials, emission fibers and related wearable fabrics with bright emission properties have become key factors for wearable applications. In ...this article, novel cuboid-like crystals of Eu3+ complexes were generated. Except for light-energy-harvesting ligands of thenoyltrifluoroacetone (TTA) and 1,10-phenanthroline hydrate (Phen), the crystal structures were adjusted by other functional amphiphilic molecules. Not only does ETPC-SA, adjusted by stearic acid, have a regular cuboid-like crystal with a size of about 2 μm size, but it also generates the best photon emission property, with a fluorescence quantum yield of 98.4% fluorescence quantum yield in this report. Furthermore, we succeeded in producing novel fluorescent fibers by mini-twin-screw extrusion, and it was easy to form bright red fabrics, which are equipped with strong fluorescence intensity, flexibility, and a smooth hand feeling, with the normal fabricating method in our work. It is worth noting that ETPC-HQ fibers, which carry a crystal complex adjusted by hydroquinone, possess the lowest quantum yield but have the longest average fluorescence lifetime of 1259 µs. This result means that a low-density polyethylene (LDPE) matrix could make excited electrons stand in the excited state for a relatively long time when adjusted by hydroquinone, so as to increase the afterglow property of fluorescent fibers.
We report the discovery of eight gamma-ray pulsars in blind frequency searches using the LAT, onboard the Fermi Gamma-ray Space Telescope. Five of the eight pulsars are young (tau_c<100 kyr), ...energetic (Edot>10^36 erg/s), and located within the Galactic plane (|b|<3 deg). The remaining three are older, less energetic, and located off the plane. Five pulsars are associated with sources included in the LAT bright gamma-ray source list, but only one, PSR J1413-6205, is clearly associated with an EGRET source. PSR J1023-5746 has the smallest characteristic age (tau_c=4.6 kyr) and is the most energetic (Edot=1.1E37 erg/s) of all gamma-ray pulsars discovered so far in blind searches. PSRs J1957+5033 and J2055+25 have the largest characteristic ages (tau_c~1 Myr) and are the least energetic (Edot~5E33 erg/s) of the newly-discovered pulsars. We present the timing models, light curves, and detailed spectral parameters of the new pulsars. We used recent XMM observations to identify the counterpart of PSR J2055+25 as XMMU J205549.4+253959. In addition, publicly available archival Chandra X-ray data allowed us to identify the likely counterpart of PSR J1023-5746 as a faint, highly absorbed source, CXOU J102302.8-574606. The large X-ray absorption indicates that this could be among the most distant gamma-ray pulsars detected so far. PSR J1023-5746 is positionally coincident with the TeV source HESS J1023-575, located near the young stellar cluster Westerlund 2, while PSR J1954+2836 is coincident with a 4.3 sigma excess reported by Milagro at a median energy of 35 TeV. Deep radio follow-up observations of the eight pulsars resulted in no detections of pulsations and upper limits comparable to the faintest known radio pulsars, indicating that these can be included among the growing population of radio-quiet pulsars in our Galaxy being uncovered by the LAT, and currently numbering more than 20.
In this work, a new photovoltaic device was prepared. The device uses titanium (Ti) foil/TiO2 nanotubes as the photoanode and multi-walled carbon nanotubes (MWCNTs) as a photosensitizer. Titanium ...dioxide nanotube arrays (TiO2-NTs) were prepared by one-step anodic oxidation. Cut-MWCNTs with a length of less than 100 nm were obtained by the mixed-acid oxidation of MWCNTs. The two materials were combined to form a TiO2-NTs@cut-MWCNT heterostructure by electrophoresis. TiO2-NTs@cut-MWCNTs were characterized by field-emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD), which showed that the two materials were effectively combined. We fabricated the heterostructure into a photovoltaic device, showing an enhanced photocurrent response and an efficiency of 0.0138%, and explained this phenomenon by performing UV-vis absorption spectroscopy and electrochemical tests. It is hoped that this work can provide a reference value for the application of carbon nanotubes in photovoltaic devices.
Objective: We aimed at evaluating whether the addition of low-dose metformin to dietary treatment could be an effective approach in nondiabetic patients with nonalcoholic fatty liver disease (NAFLD). ...Methods: We carried out a 6-month prospective study in a series of overweight or obese patients with ultrasonographic diagnosis of hepatic steatosis. In total, 50 patients were enrolled and randomized into two groups: the first group (n=25) was given metformin (1 g per day) plus dietary treatment and the second group (n=25) was given dietary treatment alone. Results: At the end of the study, the proportion of patients with echographic evidence of fatty liver was reduced in both the metformin (P<0.0001) and the diet group (P=0.029). Moreover, patient body mass index and waist circumference significantly decreased in both groups (P<0.001). Fasting glucose, insulin resistance (evaluated as homeostasis model assessment of insulin resistance (HOMA-IR)) and serum adiponectin decreased in both groups, although these changes reached statistical significance only in the metformin group. In this group, HOMA-IR decreased from 3.3±1.6 to 2.4±1.2 (P=0.003), whereas it decreased from 3.2±1.6 to 2.8±1.1 (not significant, NS) in the diet group. Similarly, the proportion of patients with impaired fasting glucose declined from 35 to 5% (P=0.04) in the metformin and from 32 to 12% (NS) in the diet group. At baseline, approximately 40% of patients in both groups met the diagnostic criteria of metabolic syndrome. This proportion decreased to 20% in the metformin group (P=0.008) and to 32% in the diet group (NS). Conclusions: In our 6-month prospective study, both low-dose metformin and dietary treatment alone ameliorated liver steatosis and metabolic derangements in patients with NAFLD. However, metformin was more effective than dietary treatment alone in normalizing several metabolic parameters in these patients.
Purpose of Review
Polycystic ovary syndrome (PCOS) is the most common endocrine and metabolic disorder in women of reproductive age worldwide. This disease causes menstrual, metabolic, and ...biochemical abnormalities such as hyperandrogenism, oligo-anovulatory menstrual cycles, polycystic ovary, hyperleptinemia, insulin resistance (IR), and cardiometabolic disorders, often associated with overweight or obesity and visceral adiposity.
Recent Findings
The etiology and pathophysiology of PCOS are not yet fully understood, but insulin seems to play a key role in this disease. PCOS shares an inflammatory state with other chronic diseases such as obesity, type II diabetes, and cardiovascular diseases; however, recent studies have shown that a healthy nutritional approach can improve IR and metabolic and reproductive functions, representing a valid therapeutic strategy to ameliorate PCOS symptomatology.
Summary
This review aimed to summarize and collect evidence about different nutritional approaches such as the Mediterranean diet (MedDiet) and the ketogenic diet (KD), as well as bariatric surgery and nutraceutical supplementation as probiotics, prebiotics, and synbiotics, among the others, used in patients with PCOS.
Polymer solar cells (PSCs) have shown excellent photovoltaic performance, however, extending the spectral response range to the ultraviolet (UV) region and enhancing the UV light stability remain two ...challenges to overcome in the development of PSCs. Lanthanide down-conversion materials can absorb the UV light and re-emit it at the visible region that matches well with the absorption of the active layer material PTB7-Th (poly2,6'-4,8-di(5-ethylhexylthienyl)benzo1,2-b;3,3-bdithiophene3-fluoro-2(2-ethylhexyl)carbonythieno3,4-bthiophenediyl) and PBDB-T-2F, thus helping to enhance the photovoltaic performance and UV light stability of PSCs. In this research, a down-conversion material Eu(TTA)
phen (ETP) is introduced into the cathode transport layer (ZnO) in PSCs to manipulate its nanostructure morphology for its application in hyperfine structure of PSCs. The device based on the ZnO/ETP electron transport layer can obtain power conversion efficiencies (PCEs) of 9.22% (PTB7-Th-PC
BM (6,6-phenylC
-butyric acid methyl ester) device) and 13.12% (PBDB-T-2F-IT-4F device), respectively. Besides, in the research on PTB7-Th-PC
BM device, the stability of the device based on ZnO/ETP layer is prolonged by 70% compared with the ZnO device. The results suggest that the ZnO/ETP layer plays the role of enhanced photovoltaic performance and prolonged device stability, as well as reducing photo-loss and UV degradation for PSCs.
PSR J0357+3205: THE TAIL OF THE TURTLE Marelli, M; De Luca, A; Salvetti, D ...
The Astrophysical journal,
03/2013, Letnik:
765, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Using a new XMM-Newton observation, we have characterized the X-ray properties of the middle-aged radio-quiet y-ray pulsar J0357+3205 (named Morla) and its tail. The X-ray emission from the pulsar is ...consistent with a magnetospheric non-thermal origin plus a thermal emission from a hot spot (or hot spots). The lack of a thermal component from the whole surface makes Morla the coldest neutron star in its age range. We found marginal evidence for a double-peaked modulation of the X-ray emission. The study of the 9' long tail confirmed the lack of extended emission near the pulsar itself. The tail shows a very asymmetric brightness profile and its spectrum lacks any spatial variation. We found the nebular emission to be inconsistent with a classical bow shock, ram-pressure-dominated pulsar wind nebula. We propose thermal bremsstrahlung as an alternative mechanism for Morla's tail emission. In this scenario, the tail emission comes from the shocked interstellar medium (ISM) material heated up to X-ray temperatures. This can fully explain the peculiar features of the tail, assuming a hot, moderately dense ISM around the pulsar. For a bremsstrahlung-emitting tail, we can estimate the pulsar distance to be between 300 and 900 pc. A pulsar velocity of ~1900 km s super(-1) is required, which would make Morla the pulsar with the largest velocity, and high inclination angles (>70degrees) are preferred. We propose Morla's nebula as the first example of a new "turtle's tail" class of thermally emitting nebulae associated with high-velocity pulsars.
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•MOFs was synthesized through one-pot synthesis at room temperature.•Real-time observation of doxorubicin loading/release from MOFs by fluorescence.•Fluorescence intensity enhancement ...after the pH-triggered doxorubicin release.•The addition of histidine polypeptides increases uptake by HepG-2 cells.
Histidine Polypeptide-Hybridized Nanoscale Metal–Organic Framework (fH12/ZIF-8) can be produced effectively in water at room temperature without using any additives. The fluorescein label also provides a useful method to quantify the extent to which the anti-cancer drug doxorubicin (DOX) is loaded into or released from the resulting MOFs. In vitro studies have shown that fH12/ZIF-8 has the useful property of dissolving and controlled rates at low pH. It ruptured fastest in PBS buffer solution with pH 6.3, and the release rate reached 50% at 4 h. Furthermore, it showed that the addition of histidine polypeptides increases uptake by HepG-2 cells. This study integrates drug loading and detecting aspects into a single theranostic platform by a simple and efficient strategy, opening a new route for the construction of advanced drug delivery systems.
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