943 research outputs found
4-(Imidazol-1-yl)benzoic acid
In the title molecule, C10H8N2O2, the imidazole and benzene rings form a dihedral angle of 14.5 (1)°. In the crystal, intermolecular O—H⋯N hydrogen bonds link the molecules into chains extending in [01], which are further linked into sheets parallel to (102) through weak C—H⋯O interactions
Computer–Aided Simulation of Mastoidectomy
AbstractObjectiveTo establish a three–dimensional model of the temporal bone using CT scan images for study of temporal bone structures and simulation of mastoidectomy procedures.MethodsCT scan images from 6 individuals (12 temporal bones) were used to reconstruct the Fallopian canal, internal auditory canal, cochlea, semicircular canals, sigmoid sinus, posterior fossa floor and jugular bulb on a computer platform. Their anatomical relations within the temporal bone were restored in the computed model. The same model was used to simulate mastoidectomy procedures.ResultsThe reconstructed computer model provided accurate and clear three–dimensional images of temporal bone structures. Simulation of mastoidectomy using these images provided procedural experiences closely mimicking the real surgical procedure.ConclusionComputer–aided three dimensional reconstruction of temporal bone structures using CT scan images is a useful tool in surgical simulation and can aid surgical procedure planning. Key words three–dimension reconstruction, CT scan, surgery simulatio
Computational Search for Two-Dimensional Photocatalysts
To overcome current serious energy and environmental issues, photocatalytic
water splitting holds great promise because it requires only solar energy as an
energy input to produce hydrogen. Two-dimensional (2D) semiconductors and
heterostructures possess several inherent advantages which are more suitable
for boosting solar energy than their bulk counterparts. In this work, by
performing high-throughput first-principles calculations combined with a
semiempirical van der Waals dispersion correction, we first provided the
periodic table of band alignment type for van der Waals heterostructures when
packing any two of the 260 semiconductor monolayers obtained from our 2D
semiconductor database (2DSdb) (https://materialsdb.cn/2dsdb/index.html). Based
on the rules of thumb for photocatalytic water splitting, we have further
screened dozens of potential semiconductors and thousands of heterostructures
which are promising for photocatalytic water splitting. The resulting database
would provide a useful guidance for experimentalists to design suitable 2D
vdWHs and photocatalysts according to desired applications.Comment: 7 pages, 4 figure
Host-Guest Complexation of Amphiphilic Molecules at the Air-Water Interface Prevents Oxidation by Hydroxyl Radicals and Singlet Oxygen
The oxidation of antioxidants by oxidizers imposes great challenges to both living organisms and the food industry. Here we show that the host–guest complexation of the carefully designed, positively charged, amphiphilic guanidinocalix[5]arene pentadodecyl ether (GC5A‐12C) and negatively charged oleic acid (OA), a well‐known cell membrane antioxidant, prevents the oxidation of the complex monolayers at the air–water interface from two potent oxidizers hydroxyl radicals (OH) and singlet delta oxygen (SDO). OH is generated from the gas phase and attacks from the top of the monolayer, while SDO is generated inside the monolayer and attacks amphiphiles from a lateral direction. Field‐induced droplet ionization mass spectrometry results have demonstrated that the host–guest complexation achieves steric shielding and prevents both types of oxidation as a result of the tight and “sleeved in” physical arrangement, rather than the chemical reactivity, of the complexes
Host-Guest Complexation of Amphiphilic Molecules at the Air-Water Interface Prevents Oxidation by Hydroxyl Radicals and Singlet Oxygen
The oxidation of antioxidants by oxidizers imposes great challenges to both living organisms and the food industry. Here we show that the host–guest complexation of the carefully designed, positively charged, amphiphilic guanidinocalix[5]arene pentadodecyl ether (GC5A‐12C) and negatively charged oleic acid (OA), a well‐known cell membrane antioxidant, prevents the oxidation of the complex monolayers at the air–water interface from two potent oxidizers hydroxyl radicals (OH) and singlet delta oxygen (SDO). OH is generated from the gas phase and attacks from the top of the monolayer, while SDO is generated inside the monolayer and attacks amphiphiles from a lateral direction. Field‐induced droplet ionization mass spectrometry results have demonstrated that the host–guest complexation achieves steric shielding and prevents both types of oxidation as a result of the tight and “sleeved in” physical arrangement, rather than the chemical reactivity, of the complexes
Clinical Evaluation of Acupuncture as Treatment for Complications of Cerebrovascular Accidents: A Randomized, Sham-Controlled, Subject- and Assessor-Blind Trial
Background and Purpose. The effect of acupuncture as treatment for poststroke complications is questionable. We performed a randomized, sham-controlled double-blind study to investigate it. Methods. Patients with first-time acute stroke were randomized to receive 24 sessions of either real or sham acupuncture during an eight-week period. The primary outcome measure was change in National Institute of Health Stroke Scale (NIHSS) score. Secondary outcome measures included changes in Barthel Index (BI), Instrumental Activities of Daily Living (IADL), Hamilton Depression Rating Scale (HAM-D), and Visual Analogue Scale (VAS) for pain scores. Results. Of the 52 patients who were randomized to receive acupuncture (n=28) or placebo (n=24), 10 patients in the acupuncture group and 9 patients in the placebo group failed to complete the treatment. In total, 18 patients in the acupuncture group and 15 patients in the control group completed the treatment course. Reduction in pain was significantly greater in the acupuncture group than in the control group (p value = 0.04). There were no significant differences in the other measures between the two groups. Conclusions. Acupuncture provided more effective poststroke pain relief than sham acupuncture treatment. However, acupuncture had no better effect on neurological, functional, and psychological improvement
Exclusive Semileptonic Rare Decays in a SUSY SO(10) GUT
In the SUSY SO(10) GUT context, we study the exclusive processes . Using the Wilson coefficients of relevant
operators including the new operators which are induced by
neutral Higgs boson (NHB) penguins, we evaluate some possible observables
associated with these processes like, the invariant mass spectrum (IMS), lepton
pair forward backward asymmetry (FBA), lepton polarization asymmetries etc. In
this model the contributions from Wilson coefficients ,
among new contributions, are dominant. Our results show that the NHB effects
are sensitive to the FBA, , and of decay, which are expected to be measured in B factories, and the
average of the normal polarization can reach several percent for
and it is 0.05 or so for , which
could be measured in the future super B factories and provide a useful
information to probe new physics and discriminate different models.Comment: 16 pages,7 figure
Biphasic Effect of Curcumin on Morphine Tolerance: A Preliminary Evidence from Cytokine/Chemokine Protein Array Analysis
The aim of this study was to evaluate the effect of curcumin on morphine tolerance and the corresponding cytokine/chemokine changes. Male ICR mice were made tolerant to morphine by daily subcutaneous injection for 7 days. Intraperitoneal injections of vehicle, low-dose or high-dose curcumin were administered 15 min after morphine injection, either acutely or chronically for 7 days to test the effect of curcumin on morphine-induced antinociception and development of morphine tolerance. On day 8, cumulative dose-response curves were generated and the 50% of maximal analgesic dose values were calculated and compared among groups. Corresponding set of mice were used for analyzing the cytokine responses by antibody-based cytokine protein array. Acute, high-dose curcumin enhanced morphine-induced antinociception. While morphine tolerance was attenuated by administration of low-dose curcumin following morphine injections for 7 days, it was aggravated by chronic high-dose curcumin following morphine injection, suggesting a biphasic effect of curcumin on morphine-induced tolerance. Of the 96 cytokine/chemokines analyzed by mouse cytokine protein array, 14 cytokines exhibited significant changes after the different 7-day treatments. Mechanisms for the modulatory effects of low-dose and high-dose curcumin on morphine tolerance were discussed. Even though curcumin itself is a neuroprotectant and low doses of the compound serve to attenuate morphine tolerance, high-doses of curcumin might cause neurotoxicity and aggravate morphine tolerance by inhibiting the expression of antiapoptotic cytokines and neuroprotective factors. Our results indicate that the effect of curcumin on morphine tolerance may be biphasic, and therefore curcumin should be used cautiously
Clinical Evaluation of Acupuncture as Treatment for Complications of Cerebrovascular Accidents: A Randomized, Sham-Controlled, Subject-and Assessor-Blind Trial
Background and Purpose. The effect of acupuncture as treatment for poststroke complications is questionable. We performed a randomized, sham-controlled double-blind study to investigate it. Methods. Patients with first-time acute stroke were randomized to receive 24 sessions of either real or sham acupuncture during an eight-week period. The primary outcome measure was change in National Institute of Health Stroke Scale (NIHSS) score. Secondary outcome measures included changes in Barthel Index (BI), Instrumental Activities of Daily Living (IADL), Hamilton Depression Rating Scale (HAM-D), and Visual Analogue Scale (VAS) for pain scores. Results. Of the 52 patients who were randomized to receive acupuncture ( = 28) or placebo ( = 24), 10 patients in the acupuncture group and 9 patients in the placebo group failed to complete the treatment. In total, 18 patients in the acupuncture group and 15 patients in the control group completed the treatment course. Reduction in pain was significantly greater in the acupuncture group than in the control group ( value = 0.04). There were no significant differences in the other measures between the two groups. Conclusions. Acupuncture provided more effective poststroke pain relief than sham acupuncture treatment. However, acupuncture had no better effect on neurological, functional, and psychological improvement
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