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1.
Med J Malaysia ; 76(6): 927-929, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34806688

RESUMO

Severe dengue infection is life threatening as it can result in fatal complications such as intractable bleeding from coagulopathy, multiorgan failure from shock and haemophagocytic syndrome. There have been case reports of atypical manifestation of severe dengue infection such as pancreatitis, Guillian-Barre's syndrome, perforated viscus and myocarditis. However, to our knowledge, pancreatic pseudocyst from dengue-related pancreatitis has never been reported in the literature. We hereby report a case of infected pancreatic pseudocyst in a patient with persistent pyrexia, abdominal pain and raised inflammatory markers 10 weeks from the onset of severe dengue infection. Endoscopic ultrasound (EUS) guided transluminal drainage of the infected pancreatic pseudocyst with lumen-apposing metallic stent (LAMS) was performed with good clinical and radiological outcome.


Assuntos
Pseudocisto Pancreático , Pancreatite , Dengue Grave , Drenagem , Endossonografia , Humanos , Pseudocisto Pancreático/complicações , Pseudocisto Pancreático/etiologia , Dengue Grave/complicações
2.
Phys Chem Chem Phys ; 22(4): 2414-2423, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31939468

RESUMO

The effects of solvents and temperature on the crystal formation were investigated for vinylidene fluoride/trifluoroethylene copolymer P(VDF-TrFE). Highly crystalline P(VDF-TrFE) thin films were fabricated by spin-casting using various polar solvents such as diethyl carbonate (DEC), methyl ethyl ketone (MEK), N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). Ferroelectric polarisation reversal of the P(VDF-TrFE) was evidenced by a displacement (D)-electric field (E) hysteresis loop measurement and supported by the presence of pyroelectric activity. The samples which were annealed above 100 °C gave elongated rod-like crystalline structures and the highest crystallinity, Xc of 83% was formed at 120 °C. Consequently, remnant polarisation (85 mC m-2) and the pyroelectric coefficient (30 µC m-2 K-1) were enhanced. Thus, annealing plays a substantial role in controlling the crystalline structure of P(VDF-TrFE) films regardless of the choice of solvent. Although, the crystalline structure control is almost independent of the solvent's polarity, the choice of solvent is essential in preparing a smoother film surface. Molecular dynamics of P(VDF-TrFE) are discussed from the observation of two dielectric relaxation processes, ß and γ related to the segmental micro-Brownian and local modes, respectively. The complete ferroelectric polarization reversal caused a reduction in the dielectric polarization and reduced the lattice spacing of the 110/200 planes.

3.
Nature ; 497(7451): 591-3, 2013 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-23719460

RESUMO

Magnetars are neutron stars with X-ray and soft γ-ray outbursts thought to be powered by intense internal magnetic fields. Like conventional neutron stars in the form of radio pulsars, magnetars exhibit 'glitches' during which angular momentum is believed to be transferred between the solid outer crust and the superfluid component of the inner crust. The several hundred observed glitches in radio pulsars and magnetars have involved a sudden spin-up (increase in the angular velocity) of the star, presumably because the interior superfluid was rotating faster than the crust. Here we report X-ray timing observations of the magnetar 1E 2259+586 (ref. 8), which exhibited a clear 'anti-glitch'--a sudden spin-down. We show that this event, like some previous magnetar spin-up glitches, was accompanied by multiple X-ray radiative changes and a significant spin-down rate change. Such behaviour is not predicted by models of neutron star spin-down and, if of internal origin, is suggestive of differential rotation in the magnetar, supporting the need for a rethinking of glitch theory for all neutron stars.

4.
Ergonomics ; 62(4): 537-547, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30482109

RESUMO

Measurement of postural stability is crucial for identifying predictors of performance, determining the efficacy of physical training and rehabilitation techniques and evaluating and preventing injuries, particularly for heavy load carriage in hikers, mountain search and rescue personnel and soldiers. This study investigated the effect of load distribution on postural stability in an upright stance using backpack and double pack loads under conflicting or impaired somatosensory, visual and vestibular conditions. The sensory organisation tests were conducted on 20 young adults before and after a 10-min level walking exercise. Young adults' ability to use inputs from somatosensory and visual systems to maintain postural stability was significantly reduced following a 10-min walking exercise with a heavy backpack (30% of body weight), whereas no significant changes were observed for double pack carriage. Thus, the distribution of heavy loads to the front and back provides superior balance control compared with back-only loading. Practitioner summary: This study investigated the effects of heavy (30% of body weight) load distribution on postural stability after a 10-min walking exercise. Backpack carriage significantly reduced postural stability, whereas there was no significant effect under double pack loads. Distribution of heavy loads on the front-and-back is desirable for superior balance control.


Assuntos
Dorso/fisiologia , Equilíbrio Postural , Postura , Caminhada/fisiologia , Suporte de Carga , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
5.
Lupus ; 27(11): 1828-1837, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30134759

RESUMO

Background Cutaneous lupus erythematosus (CLE) includes a broad range of dermatologic manifestations. Periorbital involvement, however, is a relatively rare clinical presentation of CLE. Objectives This clinical study aimed to investigate the characteristics of this unique presentation of CLE in tertiary medical centers. Methods We enrolled patients with periorbital erythema and swelling as the presenting sign of lupus erythematosus, from January 2003 to November 2017, using the data of 553 pathologically proven CLE cases from the registration database of the Chang Gung Memorial Hospitals in Taiwan. Results We enrolled a total of 25 patients. The mean age was 46.7 years and 68% of the patients were female. Most of the patients (84.0%) presented with unilateral involvement, with the left orbit involved in 15 patients (60%); the upper eyelid was the most frequently involved (72%). Mean duration between the onset of clinical manifestations and the diagnosis of CLE was approximately 59 weeks. Nineteen patients had been previously misdiagnosed. All patients had features compatible with CLE on histopathological examination. In contrast, laboratory analysis of the autoimmune profile often revealed negative results, including those for antinuclear antibodies (25%). Notably, anti-SSA/SSB (45.5%) showed the highest positive rate. During follow-up, six patients developed systemic lupus erythematosus (SLE) and two patients developed Sjögren syndrome. Conclusions The diagnosis of CLE presenting as periorbital erythema and swelling is often delayed because of clinical mimicry and the high proportion of negative results on autoantibody tests. Increased clinical suspicion and prompt histopathological examination are crucial for early diagnosis. Moreover, one-fourth of the patients ultimately developed SLE, which highlights the importance of clinical awareness.


Assuntos
Edema/patologia , Eritema/patologia , Lúpus Eritematoso Cutâneo/diagnóstico , Lúpus Eritematoso Cutâneo/patologia , Pele/patologia , Adulto , Idoso , Anticorpos Antinucleares/análise , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Taiwan , Centros de Atenção Terciária , Adulto Jovem
6.
Hum Factors ; : 18720818799190, 2018 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-30216092

RESUMO

OBJECTIVE: To investigate gender differences in energy expenditure during walking with backpack and double-pack loads. BACKGROUND: Studies have reported that energy expenditure during walking with double-pack loads is lower compared with backpack carriage. However, the effect of gender on energy expenditure while walking with these two load distribution systems has not been investigated. METHOD: Thirty healthy young adults (15 female and 15 male participants) walked on a treadmill with backpack and double-pack loads weighing 30% of their body weight at a speed of 0.89 m/s for 10 min. The energy expenditure in terms of oxygen consumption (VO2) and respiratory exchange ratio (RER) were continuously monitored using a portable gas analyzer throughout each walking exercise. A mixed-design analysis of variance model was adopted to test the effects of gender, pack, and time on VO2 and RER. RESULTS: No time effect was observed on VO2. However, significant gender, pack, and interaction effects were observed. The lowest VO2 was found in female participants under double-pack carriage. No significant gender or pack differences existed in RER. However, RER significantly and incrementally increased in time from the 4th through 6th, 8th, and 10th min. CONCLUSION: This study revealed that heavy double-pack load carriage for healthy young female participants had significantly lower energy expenditure (normalized by the entire system weight, i.e., the participant's weight plus the weight of the pack) than that of the male participants in a 10-min walking exercise. APPLICATION: The findings of this study indicated that healthy young female participants carried a heavy double-pack with less energy cost (normalized by the entire system weight, i.e., the participant's weight plus the weight of the pack) compared with their male counterparts during a 10-min walking exercise.

7.
Br J Dermatol ; 177(4): 967-977, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28160277

RESUMO

Evidence on whether patients with psoriasis have a higher risk for staphylococcal colonization than healthy controls remains controversial. To synthesize the current literature, we performed a systematic review on the prevalence and relative risk (RR) of Staphylococcus aureus colonization in patients with psoriasis. We modified the QUADAS-2 instrument to assess the reporting quality of individual studies and applied random-effects models in meta-analysis. Overall we identified 21 eligible studies, of which 15 enrolled one or more comparison groups. The pooled prevalence of staphylococcal colonization in patients with psoriasis was 35·3% [95% confidence interval (CI) 25·0-45·6] on lesional skin and 39·2% (95% CI 33·7-44·8) in the nares. Patients with psoriasis were 4·5 times more likely to be colonized by S. aureus than healthy controls were on the skin (RR 5·54, 95% CI 3·21-9·57) and 60% more in the nares (RR 1·60, 95% CI 1·11-2·32). Cutaneous and nasal colonization by meticillin-resistant S. aureus also appeared higher in patients with psoriasis (pooled prevalence 8·6%) than in healthy controls (2·6%), yet the difference was not statistically significant (P = 0·74). In contrast, despite of a similar risk for nasal staphylococcal colonization (RR 0·67, 95% CI 0·38-1·18), patients with psoriasis were less likely to carry S. aureus on lesional skin than atopic patients (RR 0·64, 95% CI 0·40-1·02). In summarizing the current literature, we found that patients with psoriasis were at an increased risk for staphylococcal colonization compared with healthy individuals. Prospective studies on how bacterial loads correlate with disease activity can guide the clinical management of bacterial colonization while preventing the emergence of drug-resistant strains.


Assuntos
Psoríase/complicações , Infecções Estafilocócicas/etiologia , Infecções Cutâneas Estafilocócicas/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Métodos Epidemiológicos , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Staphylococcus aureus Resistente à Meticilina , Pessoa de Meia-Idade , Staphylococcus aureus , Adulto Jovem
8.
Phys Chem Chem Phys ; 19(13): 8694-8705, 2017 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-28295117

RESUMO

We report detailed quantum-rovibrational-state-selected integral cross sections for the formation of H3O+via H-transfer (σHT) and H2DO+via D-transfer (σDT) from the reaction in the center-of-mass collision energy (Ecm) range of 0.03-10.00 eV, where (vvv) = (000), (100), and (020) and . The Ecm inhibition and rotational enhancement observed for these reactions at Ecm < 0.5 eV are generally consistent with those reported previously for H2O+ + H2(D2) reactions. However, in contrast to the vibrational inhibition observed for the latter reactions at low Ecm < 0.5 eV, both the σHT and σDT for the H2O+ + HD reaction are found to be enhanced by (100) vibrational excitation, which is not predicted by the current state-of-the-art theoretical dynamics calculations. Furthermore, the (100) vibrational enhancement for the H2O+ + HD reaction is observed in the full Ecm range of 0.03-10.00 eV. The fact that vibrational enhancement is only observed for the reaction of H2O+ + HD, and not for H2O+ + H2(D2) reactions suggests that the asymmetry of HD may play a role in the reaction dynamics. In addition to the strong isotopic effect favoring the σHT channel of the H2O+ + HD reaction at low Ecm < 0.5 eV, competition between the σHT and σDT of the H2O+ + HD reaction is also observed at Ecm = 0.3-10.0 eV. The present state-selected study of the H2O+ + HD reaction, along with the previous studies of the H2O+ + H2(D2) reactions, clearly shows that the chemical reactivity of H2O+ toward H2 (HD, D2) depends not only on Ecm, but also on the rotational and vibrational states of H2O+(X2B1). The detailed σHT and σDT values obtained here with single rovibrational-state selections of the reactant H2O+ are expected to be valuable benchmarks for state-of-the-art theoretical calculations on the chemical dynamics of the title reaction.

9.
Phys Chem Chem Phys ; 19(14): 9592-9605, 2017 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-28345688

RESUMO

We report on the successful implementation of a high-resolution vacuum ultraviolet (VUV) laser pulsed field ionization-photoion (PFI-PI) detection method for the study of unimolecular dissociation of quantum-state- or energy-selected molecular ions. As a test case, we have determined the 0 K appearance energy (AE0) for the formation of methylium, CH3+, from methane, CH4, as AE0(CH3+/CH4) = 14.32271 ± 0.00013 eV. This value has a significantly smaller error limit, but is otherwise consistent with previous laboratory and/or synchrotron-based studies of this dissociative photoionization onset. Furthermore, the sum of the VUV laser PFI-PI spectra obtained for the parent CH4+ ion and the fragment CH3+ ions of methane is found to agree with the earlier VUV pulsed field ionization-photoelectron (VUV-PFI-PE) spectrum of methane, providing unambiguous validation of the previous interpretation that the sharp VUV-PFI-PE step observed at the AE0(CH3+/CH4) threshold ensues because of higher PFI detection efficiency for fragment CH3+ than for parent CH4+. This, in turn, is a consequence of the underlying high-n Rydberg dissociation mechanism for the dissociative photoionization of CH4, which was proposed in previous synchrotron-based VUV-PFI-PE and VUV-PFI-PEPICO studies of CH4. The present highly accurate 0 K dissociative ionization threshold for CH4 can be utilized to derive accurate values for the bond dissociation energies of methane and methane cation. For methane, the straightforward application of sequential thermochemistry via the positive ion cycle leads to some ambiguity because of two competing VUV-PFI-PE literature values for the ionization energy of methyl radical. The ambiguity is successfully resolved by applying the Active Thermochemical Tables (ATcT) approach, resulting in D0(H-CH3) = 432.463 ± 0.027 kJ mol-1 and D0(H-CH3+) = 164.701 ± 0.038 kJ mol-1.

10.
Phys Chem Chem Phys ; 19(15): 9778-9789, 2017 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-28352920

RESUMO

We report detailed absolute integral cross sections (σ's) for the quantum-rovibrational-state-selected ion-molecule reaction in the center-of-mass collision energy (Ecm) range of 0.05-10.00 eV, where (vvv) = (000), (100), and (020), and . Three product channels, HCO+ + OH, HOCO+ + H, and CO+ + H2O, are identified. The measured σ(HCO+) curve [σ(HCO+) versus Ecm plot] supports the hypothesis that the formation of the HCO+ + OH channel follows an exothermic pathway with no potential energy barriers. Although the HOCO+ + H channel is the most exothermic, the σ(HOCO+) is found to be significantly lower than the σ(HCO+). The σ(HOCO+) curve is bimodal, indicating two distinct mechanisms for the formation of HOCO+. The σ(HOCO+) is strongly inhibited at Ecm < 0.4 eV, but is enhanced at Ecm > 0.4 eV by (100) vibrational excitation. The Ecm onsets of σ(CO+) determined for the (000) and (100) vibrational states are in excellent agreement with the known thermochemical thresholds. This observation, along with the comparison of the σ(CO+) curves for the (100) and (000) states, shows that kinetic and vibrational energies are equally effective in promoting the CO+ channel. We have also performed high-level ab initio quantum calculations on the potential energy surface, intermediates, and transition state structures for the titled reaction. The calculations reveal potential barriers of ≈0.5-0.6 eV for the formation of HOCO+, and thus account for the low σ(HOCO+) and its bimodal profile observed. The Ecm enhancement for σ(HOCO+) at Ecm ≈ 0.5-5.0 eV can be attributed to the direct collision mechanism, whereas the formation of HOCO+ at low Ecm < 0.4 eV may involve a complex mechanism, which is mediated by the formation of a loosely sticking complex between HCO+ and OH. The direct collision and complex mechanisms proposed also allow the rationalization of the vibrational inhibition at low Ecm and the vibrational enhancement at high Ecm observed for the σ(HOCO+).

11.
J Phys Chem A ; 121(3): 669-679, 2017 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-28075604

RESUMO

The ionization energies (IEs) of TiO and TiO2 and the 0 K bond dissociation energies (D0) and the heats of formation at 0 K (ΔH°f0) and 298 K (ΔH°f298) for TiO/TiO+ and TiO2/TiO2+ are predicted by the wave-function-based CCSDTQ/CBS approach. The CCSDTQ/CBS calculations involve the approximation to the complete basis set (CBS) limit at the coupled cluster level up to full quadruple excitations along with the zero-point vibrational energy (ZPVE), high-order correlation (HOC), core-valence (CV) electronic, spin-orbit (SO) coupling, and scalar relativistic (SR) effect corrections. The present calculations yield IE(TiO) = 6.815 eV and are in good agreement with the experimental IE value of 6.819 80 ± 0.000 10 eV determined in a two-color laser-pulsed field ionization-photoelectron (PFI-PE) study. The CCSDT and MRCI+Q methods give the best predictions to the harmonic frequencies: ωe (ωe+) = 1013 (1069) and 1027 (1059) cm-1 and the bond lengths re (re+) = 1.625 (1.587) and 1.621 (1.588) Å, for TiO (TiO+) compared with the experimental values. Two nearly degenerate, stable structures are found for TiO2 cation: TiO2+(C2v) structure has two equivalent TiO bonds, while the TiO2+(Cs) structure features a long and a short TiO bond. The IEs for the TiO2+(C2v)←TiO2 and TiO2+(Cs)←TiO2 ionization transitions are calculated to be 9.515 and 9.525 eV, respectively, giving the theoretical adiabatic IE value in good agreement with the experiment IE(TiO2) = 9.573 55 ± 0.000 15 eV obtained in the previous vacuum ultraviolet (VUV)-PFI-PE study of TiO2. The potential energy surface of TiO2+ along the normal vibrational coordinates of asymmetric stretching mode (ω3+) is nearly flat and exhibits a double-well potential with the well of TiO2+ (Cs) situated around the central well of TiO2+(C2v). This makes the theoretical calculation of ω3+ infeasible. For the symmetric stretching (ω1+), the current theoretical predictions overestimate the experimental value of 829.1 ± 2.0 cm-1 by more than 100 cm-1. This work together with the previous experimental and theoretical investigations supports the conclusion that the CCSDTQ/CBS approach is capable of providing reliable IE and D0 predictions for TiO/TiO+ and TiO2/TiO2+ with error limits less than or equal to 60 meV. The CCSDTQ/CBS calculations give the predictions of D0(Ti+-O) - D0(Ti-O) = 0.004 eV and D0(O-TiO) - D0(O-TiO+) = 2.699 eV, which are also consistent with the respective experimental determination of 0.008 32 ± 0.000 10 and 2.753 75 ± 0.000 18 eV.

12.
Med J Malaysia ; 72(4): 244-245, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28889137

RESUMO

Abdominal pain is one of the common presentations in severe dengue infection. We report a rare case of perforated gastric ulcer in a young man diagnosed with severe dengue infection and the challenges we faced in managing this patient. Perforated gastric ulcer need to be considered if there are signs of peritonitis and persistent abdominal pain that does not conform to the natural history of dengue. Proper imaging and early surgical intervention in perforated gastric ulcer is vital in preventing further complication and reducing the risk of mortality.


Assuntos
Dengue/complicações , Úlcera Péptica Perfurada/etiologia , Adulto , Humanos , Masculino , Úlcera Péptica Perfurada/diagnóstico por imagem , Úlcera Péptica Perfurada/cirurgia , Úlcera Péptica Perfurada/virologia , Tomografia Computadorizada por Raios X
13.
Phys Chem Chem Phys ; 18(32): 22509-15, 2016 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-27508462

RESUMO

To understand the dynamics of H3O(+) formation, we report a combined experimental-theoretical study of the rovibrationally state-selected ion-molecule reactions H2O(+)(X(2)B1; v1(+)v2(+)v3(+); NKa(+)Kc(+)(+)) + H2 (D2) → H3O(+) (H2DO(+)) + H (D), where (v1(+)v2(+)v3(+)) = (000), (020), and (100) and NKa(+)Kc(+)(+) = 000, 111, and 211. Both quantum dynamics and quasi-classical trajectory calculations were carried out on an accurate full-dimensional ab initio global potential energy surface, which involves nine degrees of freedom. The theoretical results are in good agreement with experimental measurements of the initial state specific integral cross-sections for the formation of H3O(+) (H2DO(+)) and thus provide valuable insights into the surprising rotational enhancement and vibrational inhibition effects in these prototypical ion-molecule reactions that play a key role in the interstellar generation of OH and H2O species.

14.
Med J Malaysia ; 71(3): 99-104, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27495881

RESUMO

BACKGROUND: Chronic kidney disease (CKD) is a major health concern worldwide. There are limited studies which look into the actual knowledge level of CKD among the general population both locally and internationally. This study aims to assess the knowledge level of CKD among patients in a secondary hospital in Malaysia. METHODS: Consecutive sampling of patients attending the Medical Outpatient Clinic was performed in this crosssectional study. Respondents were given self-administered questionnaires which contain questions on demographic characteristics and knowledge on CKD. RESULTS: Out of 300 respondents, 78.6% (n=236) of the respondents completed the questionnaire. Majority of respondents (73.7%, n=174) scored less than 4 out of 7 marks on knowledge on CKD. Respondents who were younger, males, having higher education status, professionals/executives and earned higher monthly income were more likely to have a higher mean knowledge score of CKD. Respondents who have heard of CKD were also significantly associated with higher mean knowledge score of CKD. CONCLUSION: The study findings suggest that our Malaysian population is still inadequately informed on CKD, especially those who are at risk of developing CKD and its complications, and also among those of the lower socioeconomic group. In order for successful primary and secondary prevention of CKD, more importance should be placed on increasing awareness on CKD among these atrisk groups.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Insuficiência Renal Crônica , Adulto , Idoso , Instituições de Assistência Ambulatorial , Estudos Transversais , Feminino , Humanos , Malásia , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários
15.
Am J Transplant ; 15(5): 1415-20, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25772308

RESUMO

Despite advances in surgical technique and clinical care, lung transplantation still remains a short-term solution for the treatment of end-stage lung disease. To date, there has been limited experience in experimental lung transplantation using nonhuman primate models. Therefore, we have endeavored to develop a long-term, nonhuman primate model of orthotopic lung transplantation for the ultimate purpose of designing protocols to induce tolerance of lung grafts. Here, we report our initial results in developing this model and our observation that the nonhuman primate lung is particularly prone to rejection. This propensity toward rejection may be a consequence of 1) upregulated nonspecific inflammation, and 2) a larger number of pre-existing alloreactive memory T cells, leading to augmented deleterious immune responses. Our data show that triple-drug immunosuppression mimicking clinical practice is not sufficient to prevent acute rejection in nonhuman primate lung transplantation. The addition of horse-derived anti-thymocyte globulin and a monoclonal antibody to the IL-6 receptor allowed six out of six lung recipients to be free of rejection for over 120 days.


Assuntos
Pneumopatias/cirurgia , Transplante de Pulmão , Animais , Soro Antilinfocitário/química , Teste de Histocompatibilidade , Cavalos , Tolerância Imunológica , Memória Imunológica/imunologia , Terapia de Imunossupressão , Inflamação/imunologia , Pulmão/patologia , Macaca fascicularis , Complexo Principal de Histocompatibilidade , Modelos Animais , Receptores de Interleucina-6/metabolismo , Linfócitos T/citologia , Transplante Autólogo , Transplante Homólogo
16.
Phys Chem Chem Phys ; 17(17): 11752-62, 2015 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-25868654

RESUMO

The state-to-state photodissociation of CO2 is investigated in the VUV range of 11.94-12.20 eV by using two independently tunable vacuum ultraviolet (VUV) lasers and the time-sliced velocity-map-imaging-photoion (VMI-PI) method. The spin-allowed CO(X(1)Σ(+); v = 0-18) + O((1)D) and CO(X(1)Σ(+); v = 0-9) + O((1)S) photoproduct channels are directly observed from the measurement of time-sliced VMI-PI images of O((1)D) and O((1)S). The total kinetic energy release (TKER) spectra obtained based on these VMI-PI images shows that the observed energetic thresholds for both the O((1)D) and O((1)S) channels are consistent with the thermochemical thresholds. Furthermore, the nascent vibrational distributions of CO(X(1)Σ(+); v) photoproducts formed in correlation with O((1)D) differ significantly from that produced in correlation with O((1)S), indicating that the dissociation pathways for the O((1)D) and O((1)S) channels are distinctly different. For the O((1)S) channel, CO(X(1)Σ(+); v) photoproducts are formed mostly in low vibrational states (v = 0-2), whereas for the O((1)D) channel, CO(X(1)Σ(+); v) photoproducts are found to have significant populations in high vibrationally excited states (v = 10-16). The anisotropy ß parameters for the O((1)D) + CO(X(1)Σ(+); v = 0-18) and O((1)S) + CO(X(1)Σ(+); v = 0-9) channels have also been determined from the VMI-PI measurements, indicating that CO2 dissociation to form the O((1)D) and O((1)S) channels is faster than the rotational periods of the VUV excited CO2 molecules. We have also calculated the excited singlet potential energy surfaces (PESs) of CO2, which are directly accessible by VUV excitation, at the ab initio quantum multi-reference configuration interaction level of theory. These calculated PESs suggest that the formation of CO(X(1)Σ(+)) + O((1)S) photoproducts occurs nearly exclusively on the 4(1)A' PES, which is generally repulsive with minor potential energy ripples along the OC-O stretching coordinate. The formation of CO(X(1)Σ(+)) + O((1)D) photofragments can proceed by non-adiabatic transitions from the 4(1)A' PES to the lower 3(1)A' PES of CO2via the seam of conical intersections at a near linear OCO configuration, followed by the direct dissociation on the 3(1)A' PES. The theoretical PES calculations are consistent with the experimental observation of prompt CO2 dissociation and high rotational and vibrational excitations for CO(X(1)Σ(+)) photoproducts.

17.
Phys Chem Chem Phys ; 17(15): 9780-93, 2015 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-25772535

RESUMO

By employing two-color visible (VIS)-ultraviolet (UV) laser photoionization and pulsed field ionization-photoelectron (PFI-PE) techniques, we have obtained highly rotationally resolved photoelectron spectra for vanadium monocarbide cations (VC(+)). The state-to-state VIS-UV-PFI-PE spectra thus obtained allow unambiguous assignments for the photoionization rotational transitions, resulting in a highly precise value for the adiabatic ionization energy (IE) of vanadium monocarbide (VC), IE(VC) = 57512.0 ± 0.8 cm(-1) (7.13058 ± 0.00010 eV), which is defined as the energy of the VC(+)(X(3)Δ1; v(+) = 0; J(+) = 1) ← VC(X(2)Δ3/2; v'' = 0; J'' = 3/2) photoionization transition. The spectroscopic constants for VC(+)(X(3)Δ1) determined in the present study include the harmonic vibrational frequency ωe(+) = 896.4 ± 0.8 cm(-1), the anharmonicity constant ωe(+)xe(+) = 5.7 ± 0.8 cm(-1), the rotational constants Be(+) = 0.6338 ± 0.0025 cm(-1) and αe(+) = 0.0033 ± 0.0007 cm(-1), the equilibrium bond length re(+) = 1.6549 ± 0.0003 Å, and the spin-orbit coupling constant A = 75.2 ± 0.8 cm(-1) for VC(+)(X(3)Δ1,2,3). These highly precise energetic and spectroscopic data are used to benchmark state-of-the-art CCSDTQ/CBS calculations. In general, good agreement is found between the theoretical predictions and experimental results. The theoretical calculations yield the values, IE(VC) = 7.126 eV; the 0 K bond dissociation energies: D0(V-C) = 4.023 eV and D0(V(+)-C) = 3.663 eV; and heats of formation: ΔH°(f0)(VC) = 835.2, ΔH°(f298)(VC) = 840.4, ΔH°(f0)(VC(+)) = 1522.8, and ΔH°(f298)(VC(+)) = 1528.0 kJ mol(-1).

18.
J Phys Chem A ; 119(45): 11162-9, 2015 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-26485180

RESUMO

Vanadium monoxide cation VO(+)(X(3)Σ(-)) has been investigated by two-color visible (VIS)-ultraviolet (UV) pulsed field ionization-photoelectron (PFI-PE) methods. The unambiguous rotational assignment of rotationally selected and resolved VIS-UV-PFI-PE spectra thus obtained confirms the ground state term symmetry of VO(+) to be X(3)Σ(-). The rotational analysis also yields the rotational constants Be(+) = 0.5716 ± 0.0012 cm(-1) and αe(+) = 0.0027 ± 0.0005 cm(-1) for VO(+)(X(3)Σ(-)), from which the equilibrium bond distance of VO(+)(X(3)Σ(-)) is determined to be re(+) = 1.557 ± 0.002 Å. This PFI-PE study covers the vibrational bands, VO(+)(X(3)Σ(-); v(+) = 0, 1, 2, and 3) ← VO(X(4)Σ(-); v″ = 0), which has made possible the determination of the vibrational constants for VO(+)(X(3)Σ(-)) to be ωe(+) = 1068.0 ± 0.7 cm(-1) and ωe(+)xe(+) = 5.5 ± 0.7 cm(-1). The present state-to-state measurement also yields a more precise value (58 380.0 ± 0.7 cm(-1) or 7.238 20 ± 0.000 09 eV) for the ionization energy of VO [IE(VO)]. This value along with the known IE(V) has allowed the determination of the difference between the 0 K bond dissociation energy (D0) of VO(+)(X(3)Σ(-)) and that of VO(X(4)Σ(-)) to be D0(V(+)-O) - D0(V-O) = IE(V) - IE(VO) = -3967 ± 1 cm(-1).

19.
J Clin Pharm Ther ; 40(6): 689-92, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26365588

RESUMO

WHAT IS KNOWN AND OBJECTIVE: Febuxostat is recommended as an alternative drug for gouty patients with a history of allopurinol hypersensitivity or carrying the HLA-B*5801 allele. CASE SUMMARY: An 81-year-old man with the medical history of gout presented to our clinic with generalized rashes for 2 days. After taking febuxostat for 2 days, he developed generalized skin rash with high fever. Laboratory tests showed elevated liver enzymes and acute kidney injury. WHAT IS KNOWN AND OBJECTIVE: This is the first identified case of febuxostat-associated DRESS. Febuxostat should be withdrawn immediately when DRESS is observed to avoid further serious complications.


Assuntos
Síndrome de Hipersensibilidade a Medicamentos/etiologia , Eosinofilia/induzido quimicamente , Febuxostat/efeitos adversos , Idoso de 80 Anos ou mais , Febuxostat/uso terapêutico , Gota/tratamento farmacológico , Humanos , Masculino
20.
Phys Chem Chem Phys ; 16(2): 563-9, 2014 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-24166588

RESUMO

Photodissociation of CO2 is investigated between 13.540 eV and 13.678 eV using the time-sliced velocity-mapped ion imaging (TSVMI) apparatus that is combined with one-color and two-color pump-probe VUV + VUV and VUV + UV detection schemes by probing oxygen fragments at different levels. Several CO2 dissociation channels are directly observed from the ion images, namely CO(X (1)Σ(+)) + O((1)D), CO(X (1)Σ(+)) + O((1)S), CO(a (3)Π) + O((3)P), CO(a (3)Π) + O((1)D), CO(a' (3)Σ(+)) + O((3)P), CO(d (3)Δ) + O((3)P) and CO(e (3)Σ(-)) + O((3)P), whereas no CO(X (1)Σ(+)) + O((3)P) production has been found. The product kinetic energy distributions of these channels are reported for the first time. Possible dissociation mechanisms have been discussed based upon the product vibrational and rotational distributions.

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