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1.
Eur Phys J E Soft Matter ; 43(10): 64, 2020 Oct 01.
Article in English | MEDLINE | ID: mdl-33009958

ABSTRACT

Drying-induced cracking is widely encountered in nature and is of fundamental interest in industrial applications. During desiccation, the evolution of water content is nonlinear. Considering the inhomogeneous procedure of desiccation, it is worth considering whether water content will affect the crack pattern formation. To address this concern, in this paper, we report an experimental investigation on the effect of water content on the failure mode in drying colloidal films. A distinct failure transition from random cracking to curling is found when the initial water content increases gradually. When the water content is below a critical value for given film thickness, random desiccation cracking driven by shrinkage is observed. Beyond this critical water content, the film curls with the advent of several main cracks. It is also found that the critical water content corresponding to the transition point depends on the film thickness. In order to qualitatively interpret the experimental observation, a theoretical model is established by adopting the fracture mechanics based on the energy method. The model is found to agree well with the experimental results, elucidating the effects of initial water content on the crack patterns and the transition of failure modes.

2.
AJNR Am J Neuroradiol ; 41(7): 1217-1224, 2020 07.
Article in English | MEDLINE | ID: mdl-32554419

ABSTRACT

BACKGROUND AND PURPOSE: Previous studies have reported that MCA bifurcation aneurysms usually emerge on inclined bifurcations; however, the reason is unclear. We designed this study to explore hemodynamic mechanisms that correlate with the initiation of MCA bifurcation aneurysms. MATERIALS AND METHODS: Fifty-four patients with unilateral MCA bifurcation aneurysms and 54 control patients were enrolled in this study after propensity score matching, and their clinical and CTA data were collected. We extracted the morphologic features of aneurysmal MCA bifurcations to build a simplified MCA bifurcation model and performed a computational fluid dynamics analysis. RESULTS: The presence of MCA aneurysms correlated with smaller parent-daughter angles of MCA bifurcations (P < .001). Aneurysmal MCA bifurcations usually presented with inclined shapes. The computational fluid dynamics analysis demonstrated that when arterial bifurcations became inclined, the high-pressure regions and low wall shear stress regions shifted from the apexes of the arterial bifurcations to the inclined daughter arteries, while the initial sites of MCA bifurcation aneurysms often overlapped with the shifted high-pressure regions and low wall shear stress regions. CONCLUSIONS: Our results suggest that the initiation of MCA bifurcation aneurysms may correlate with shifts of high-pressure regions and low wall shear stress regions that occur on inclined MCA bifurcations.


Subject(s)
Hemodynamics/physiology , Intracranial Aneurysm/physiopathology , Adult , Cerebral Angiography/methods , Computed Tomography Angiography/methods , Female , Humans , Hydrodynamics , Male , Middle Aged , Middle Cerebral Artery , Stress, Mechanical
3.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 32(2): 159-167, 2020 Apr 24.
Article in Chinese | MEDLINE | ID: mdl-32458605

ABSTRACT

OBJECTIVE: To characterize a species of the genus Tricula and parasitized trematodes in schistosomiasis-endemic areas of Yunnan Province using a molecular analysis, so as to understand their taxonomic positions. METHODS: Tricula spp. and Oncomelania snails were collected from Xiangyun County, Yunnan Province, and cercaria parasitizing snails were observed using crushing followed by microscopy. Cercaria parasitizing Tricula snails at various morphologies were sampled using a shedding method. Genomic DNA was extracted from snail soft tissues and cercariae, and the 16S rRNA, COI, 28S rDNA genes in snails and the ND1 and 28S rDNA genes in cercariae were amplified using a PCR assay and sequenced. The species of Tricula snails and their parasitized trematodes was characterized using sequence alignment and phylogenetic analysis. RESULTS: Among 382 Tricula snails detected, there were three types of trematode cercariae found, including the non-forked (20.94%, 80/382), double-forked (3.40%, 13/382) and swallow shapes (7.07%, 27/382). Sequence and phylogenetic analyses showed that the 16S rRNA, COI and 28S rDNA gene sequences of this species of Tricula had high homology to those in Delavaya dianchiensis, and were clustered in a branch. Sequencing analysis of the ND1 and 28S rDNA genes revealed that the non-forked cercariae belonged to the family Pleu- rogenidae, the swallow-shaped cercariae belonged to the family Opecoelidae, and the double-forked cercariae belonged to another species of the genus Schistosoma that was different from S. sinensium and S. ovuncatum. CONCLUSIONS: The species and taxonomy of Triculla spp. and their parasitized trematodes are preliminarily determined in schistosomiasis-endemic areas of Yunnan Province; however, further studies are required to investigate the more definite taxonomy and pathogenicity.


Subject(s)
Cercaria , Phylogeny , Snails/classification , Snails/parasitology , Trematoda , Animals , Cercaria/genetics , Cercaria/isolation & purification , China , Electron Transport Complex IV/genetics , Endemic Diseases , NADH Dehydrogenase/genetics , RNA, Ribosomal, 16S/genetics , RNA, Ribosomal, 28S/genetics , Schistosomiasis/epidemiology , Schistosomiasis/parasitology , Snails/genetics , Trematoda/genetics , Trematoda/isolation & purification
4.
Nat Commun ; 10(1): 5605, 2019 12 06.
Article in English | MEDLINE | ID: mdl-31811130

ABSTRACT

Solitary, persistent wave packets called solitons hold potential to transfer information and energy across a wide range of spatial and temporal scales in physical, chemical, and biological systems. Mechanical solitons characteristically emerge either as a single wave packet or uncorrelated propagating topological entities through space and/or time, but these are notoriously difficult to control. Here, we report a theoretical framework for programming static periodic topological solitons into a metamaterial, and demonstrate its implementation in real metamaterials computationally and experimentally. The solitons are excited by deformation localizations under quasi-static compression, and arise from buckling-induced kink-antikink bands that provide domain separation barriers. The soliton number and wavelength demonstrate a previously unreported size-dependence, due to intrinsic length scales. We identify that these unanticipated solitons stem from displacive phase transitions with periodic topological excitations captured by the well-known [Formula: see text] theory. Results reveal pathways for robust regularizations of stochastic responses of metamaterials.

5.
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi ; 37(11): 810-814, 2019 Nov 20.
Article in Chinese | MEDLINE | ID: mdl-31826543

ABSTRACT

Objective: To research build a kind of occupational disease risk assessment model which provides scientific basis for prevention and control of occupational diseases. Methods: Based on the principle of information diffusion, this paper uses spread function to extend the incomplete gathered information, establishes the mapping relationship between observation samples and risk probability distributions, and constructs the occupational disease risk assessment model, to analyzes the risk data of occupational disease reported cases in Guangdong Province in the past five years. Results: Through evaluation analysis, every year, 200-300 cases of pneumoconiosis probability is 67.77%, 100-200 cases of occupational poisoning probability is 68.52%, 20-40 cases of occupational cancers probability is 71.62%, each year, the incidence of occupation otorhinolaryngology and oral diseases in 200 cases was 62.23%. Conclusion: A model of occupational disease risk assessment based on information diffusion theory is constructed, the evaluation result is basically consistent with the actual situation of occupational disease, which can provide reference for occupational disease prevention and control.


Subject(s)
Models, Statistical , Occupational Diseases , Humans , Incidence , Occupational Diseases/epidemiology , Occupational Diseases/prevention & control , Risk Assessment
6.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 54(7): 475-480, 2019 Jul 09.
Article in Chinese | MEDLINE | ID: mdl-31288328

ABSTRACT

Objective: To observe the effect of adenosine triphosphate (ATP) phosphorylation on type Ⅰ collagen mineralization and explore the role of small molecule compound ATP in biomimetic mineralization. Methods: Fourier transform infrared spectroscopy (FT-IR) was used to analyze the phosphorylation of collagen molecules by different concentrations (0, 25, 50, 100 mmol/L) of ATP. The concentration of 50 mmol/L ATP was chosen to construct the phosphorylated collagen mineralization model. Transmission electron microscopy (TEM) was used to observed the ultrastructure of mineralized collagen and the collagen mineralization rate was further calculated by ImageJ software. The surface morphology of the collagen gel ATP group and the control group was observed by scanning electron microscopy (SEM) and the elemental analysis was performed by using an X-ray energy spectrometer. The artificial demineralized dentin samples were mineralized for 2 days and 4 days to compare the effect of ATP on dentin remineralization by SEM. Results: FT-IR analysis showed that the formation of new peaks at wavenumbers of 642, 818, and 902 cm(-1) indicated that ATP can phosphorylate type Ⅰ collagen. Through TEM and SEM observation, the mineralization degree of type Ⅰ collagen and demineralized dentin pretreated with 50 mmol/L ATP were significantly higher than that of the control group. Compared with the control group [(31.65±1.62)%], the mineralization rate of collagen in the ATP group [(100±0)%] was significantly increased after 2 days of mineralization (P<0.05). Conclusions: ATP phosphorylation can effectively promote the mineralization process of type Ⅰ collagen.


Subject(s)
Adenosine Triphosphate , Biomimetic Materials , Collagen Type I , Adenosine Triphosphate/pharmacology , Biomimetic Materials/chemistry , Collagen Type I/chemistry , Collagen Type I/metabolism , Collagen Type I/ultrastructure , Dentin/chemistry , Dentin/ultrastructure , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Phosphorylation , Spectroscopy, Fourier Transform Infrared
7.
J Colloid Interface Sci ; 539: 379-387, 2019 Mar 15.
Article in English | MEDLINE | ID: mdl-30594833

ABSTRACT

HYPOTHESIS: Control of capillary flow through porous media has broad practical implications. However, achieving accurate and reliable control of such processes by tuning the pore size or by modification of interface wettability remains challenging. Here we propose that the liquid flow by capillary penetration can be accurately adjusted by tuning the geometry of porous media. METHODOLOGIES: On the basis of Darcy's law, a general framework is proposed to facilitate the control of capillary flow in porous systems by tailoring the geometric shape of porous structures. A numerical simulation approach based on finite element method is also employed to validate the theoretical prediction. FINDINGS: A basic capillary component with a tunable velocity gradient is designed according to the proposed framework. By using the basic component, two functional capillary elements, namely, (i) flow accelerator and (ii) flow resistor, are demonstrated. Then, multi-functional fluidic devices with controllable capillary flow are realized by assembling the designed capillary elements. All the theoretical designs are validated by numerical simulations. Finally, it is shown that the proposed concept can be extended to three-dimensional design of porous media.

8.
Eur Rev Med Pharmacol Sci ; 21(3): 627-634, 2017 02.
Article in English | MEDLINE | ID: mdl-28239802

ABSTRACT

Anesthetic management of patients with dilated cardiomyopathy (DCM) is a challenge to the anesthesiologist, due to poor left systolic function, ventricular enlargement, risk of malignant arrhythmias and sudden cardiac death. Therefore, preoperative assessment and appropriate anesthetic management are important in patients with DCM. This review describes the preoperative evaluation and anesthesia considerations of patients with DCM undergoing non-cardiac surgery. Patient pathophysiology and clinical status, such as ventricular function, degree of myocardial fibrosis, resting heart rate and high-sensitivity C-reactive protein can affect survival rates. Advanced monitoring devices, such as transesophageal echocardiography and cardiac resynchronization therapy can be used to assess ventricular function and myocardial fibrosis. Thoracic epidural blockade can improve ventricular function. In summary, the optimal anesthetic management of patients with dilated cardiomyopathy requires good preoperative assessment, close perioperative monitoring, suitable anesthetic, optimization fluid management, and stable hemodynamic status.


Subject(s)
Anesthesia/methods , Cardiomyopathy, Dilated/surgery , Arrhythmias, Cardiac , C-Reactive Protein/analysis , Cardiac Resynchronization Therapy , Cardiomyopathy, Dilated/physiopathology , Echocardiography , Fibrosis , Heart Rate , Humans , Monitoring, Physiologic , Myocardium/pathology , Preoperative Care
9.
Sci Total Environ ; 580: 1175-1184, 2017 Feb 15.
Article in English | MEDLINE | ID: mdl-27998655

ABSTRACT

Antibiotics are widely used in mariculture industry, and this study attempts to determine the extent of water and sediment pollution by antibiotic residues in 13 major mariculture sites in China. Through chemical and molecular biology analysis, the results showed that the total concentrations of sulfonamides and tetracyclines were in the range 62.0-373.8ngL-1 and 0.2-259.1ngL-1 respectively in water samples, and in the range 0.19-1.59ngg-1 dry weight and 3.45-74.84ngg-1 dry weight respectively, in sediments samples. The occurrence of antibiotic resistance genes (ARGs) was detected in all sites. Compared with the tetracyclines resistance genes, the absolute copy number and relative abundance of the sulfonamides resistance genes were 4.3 times and 2.3 times higher in water and sediment from the mariculture sites, with the dominant resistance genes being sul2. The abundance of sul3 in the water phase was significantly correlated with the concentrations of sulfamerazine, while the abundance of sul2 in the sediment phase was significantly with sulfadiazine concentrations. The abundance of tetM in the sediment phase was significantly correlated with the concentrations of oxytetracycline. The findings demonstrate the persistence of antibiotic residues and ARGs in major mariculture sites in Southeast China.


Subject(s)
Aquaculture , Drug Residues/analysis , Drug Resistance, Bacterial/genetics , Genes, Bacterial , Anti-Bacterial Agents/analysis , China , Sulfonamides/analysis , Tetracyclines/analysis
10.
Sci Rep ; 6: 33312, 2016 09 14.
Article in English | MEDLINE | ID: mdl-27624892

ABSTRACT

Origami structures enrich the field of mechanical metamaterials with the ability to convert morphologically and systematically between two-dimensional (2D) thin sheets and three-dimensional (3D) spatial structures. In this study, an in-plane design method is proposed to approximate curved surfaces of interest with generalized Miura-ori units. Using this method, two combination types of crease lines are unified in one reprogrammable procedure, generating multiple types of cylindrical structures. Structural completeness conditions of the finite-thickness counterparts to the two types are also proposed. As an example of the design method, the kinematics and elastic properties of an origami-based circular cylindrical shell are analysed. The concept of Poisson's ratio is extended to the cylindrical structures, demonstrating their auxetic property. An analytical model of rigid plates linked by elastic hinges, consistent with numerical simulations, is employed to describe the mechanical response of the structures. Under particular load patterns, the circular shells display novel mechanical behaviour such as snap-through and limiting folding positions. By analysing the geometry and mechanics of the origami structures, we extend the design space of mechanical metamaterials and provide a basis for their practical applications in science and engineering.

11.
Langmuir ; 32(38): 9899-904, 2016 09 27.
Article in English | MEDLINE | ID: mdl-27583455

ABSTRACT

The capillary penetration of fluids in thin porous layers is of fundamental interest in nature and various industrial applications. When capillary flows occur in porous media, the extent of penetration is known to increase with the square root of time following the Lucas-Washburn law. In practice, volatile liquid evaporates at the surface of porous media, which restricts penetration to a limited region. In this work, on the basis of Darcy's law and mass conservation, a general theoretical model is developed for the evaporation-limited radial capillary penetration in porous media. The presented model predicts that evaporation decreases the rate of fluid penetration and limits it to a critical radius. Furthermore, we construct a unified phase diagram that describes the limited penetration in an annular porous medium, in which the boundaries of outward and inward liquid are predicted quantitatively. It is expected that the proposed theoretical model will advance the understanding of penetration dynamics in porous media and facilitate the design of engineered porous architectures.

12.
J Biol Regul Homeost Agents ; 30(1): 197-204, 2016.
Article in English | MEDLINE | ID: mdl-27049092

ABSTRACT

The aim of this research was to study the clinical significance and expression of CD4+CD25+ regulatory T cells (Tregs) and p3Forkhead transcription factor-3 (Foxp3) in peripheral blood of patients with gastric carcinoma (GC) and to investigate the effects in the occurrence and development process of GC, to further comprehend their clinical values and provide a theoretical basis for the early diagnosis and immunotherapy of GC. The expression levels of CD4+CD25+Foxp3+Tregs in GC patients, at TNM staging, differentiated degree, lymphatic metastasis, cancer sites and cancer diameter of GC, were analyzed within the groups. The comparison of the expression levels of CD4+CD25+Foxp3+Tregs in peripheral blood between the GC group and the healthy control group showed a statistically significant difference. At TNM staging within the groups, pairwise comparisons of the expression levels of CD4+CD25+Foxp3+Tregs indicated that differences among the stage I+II group, stage III group and stage IV group were statistically significant. The expression levels of CD4+CD25+Foxp3+Tregs are closely relative to the occurrence and development of GC, providing theoretical bases and evidence for the early diagnosis, prognosis evaluation and immunotherapy of GC.


Subject(s)
Forkhead Transcription Factors/metabolism , Interleukin-2 Receptor alpha Subunit/metabolism , Stomach Neoplasms/blood , Stomach Neoplasms/immunology , T-Lymphocytes, Regulatory/immunology , Adult , Aged , Case-Control Studies , Demography , Female , Humans , Male , Middle Aged
13.
Opt Express ; 23(7): 8740-8, 2015 Apr 06.
Article in English | MEDLINE | ID: mdl-25968712

ABSTRACT

In this letter, a new kind of grating, quasi-one-dimensional gold grating, has been proposed to enhance the optical coupling in AlGaN/GaN quantum well infrared photodetector (QWIP). The electric field distribution, current density and energy flow are analyzed by an algorithm of finite element method (FEM). Significantly enhanced electric field component E(z) perpendicular to multiple quantum wells (MQWs) is explained by introducing the resonant coupling of surface plasmon polariton (SPP) and localized surface plasmon (LSP). The |E(z)|(2) in MQWs reaches 0.85 (V/m(2) when the electric field intensity (|E(0)|(2)) of normal incidence is 1 (V/m(2) at 4.65 µm, showing 2 times and 1.3 times increase compared with that obtained via a one-dimensional gold grating and a two-dimensional gold grating, respectively. The results confirm that the quasi-one-dimensional gold grating provides more plasma excitation source and higher charge density with structure optimization, resulting in a high optical coupling efficiency of 85% in quantum well region.

14.
Genet Mol Res ; 14(4): 17951-8, 2015 Dec 22.
Article in English | MEDLINE | ID: mdl-26782441

ABSTRACT

Antibody-mediated rejection (AMR) is an important factor affecting survival after renal transplantation. A highly selective proteasome inhibitor, bortezomib, clears activated plasma cells from the body and has important therapeutic effect on AMR. We investigated the effects of bortezomib on AMR in a patient after a second renal transplant. Biopsy confirmed the diagnosis of mixed cellular rejection and AMR. Bortezomib was administered on day 1 (1.3 mg/m(2)), day 4 (1.0 mg/m(2)), and day 8 (1.0 mg/m(2)). On the same days, 250 mg methylprednisolone was administered once, and cyclosporine dose (5 mg·kg(-1)·day(-1)) was reduced by 50%. Oral mycophenolate mofetil and steroid were withdrawn on day 1 of bortezomib treatment. Intermittent double-filtration plasmapheresis was also performed. We monitored parameters, including T lymphocyte subsets, CD139 and CD19 expression, panel reactive antibody (PRA), and serum creatinine concentration. At follow-up 6 months after bortezomib treatment, we observed: 1) serum creatinine stabilized at 130 µM from a peak level of 337 µM; 2) PRA decreased from a maximum of 66.7 to 0%; 3) blood plasma cell percentage rebounded after significantly decreasing following the first dose of bortezomib; 4) in renal allograft biopsy, immunohistochemical staining for C4d shifted from strongly positive to negative, and cellular rejection shifted from type IIA to borderline; and 5) adverse effects such as platelet suppression, hypotension, and grade 3 peripheral neuropathy emerged. Bortezomib effectively treated antibody-mediated renal transplantation rejection in this case study, but clinical trials with large sample sizes are still needed to explore clinical safety and tolerability.


Subject(s)
Antibodies/adverse effects , Bortezomib/adverse effects , Graft Rejection/drug therapy , Kidney Transplantation/adverse effects , Antibodies/immunology , Bortezomib/administration & dosage , Female , Graft Rejection/immunology , Graft Rejection/pathology , Humans , Kidney/drug effects , Kidney/immunology , Kidney/pathology , Mycophenolic Acid/administration & dosage , Mycophenolic Acid/analogs & derivatives , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/pathology , Transplantation, Homologous/adverse effects
15.
Ultrasonics ; 55: 42-7, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25200701

ABSTRACT

Coupled shear (SH) elastic and electromagnetic (EM) waves propagating oblique to a one dimensional periodic piezoelectric and piezomagnetic composite are investigated using the transfer matrix method. Closed-form expression of the dispersion relations is derived. We find that the band structures of the periodic composite show simultaneously the features of phononic and photonic crystals. Strong interaction between the elastic and EM waves near the center of the Brillouin zone (i.e., phonon-polariton) is revealed. It is shown the elastic branch of the band structures is more sensitive to the piezoelectric effect while the phonon-polariton is more sensitive to the piezomagnetic effect of the composite.

16.
Eur Rev Med Pharmacol Sci ; 18(22): 3368-79, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25491610

ABSTRACT

OBJECTIVE: Data regarding the cerebral atherosclerotic stenosis (CAS) and incidence of stroke are conflicting. The number of stroke patients is more than three times that from coronary heart disease in China. The main aim of this report is to review the current status of intracranial and extracranial atherosclerotic stenosis including epidemiology, diagnosis, treatment and risk factors in China. METHODS: Data was identified by searches of MEDLINE (January 1966 to December 2008), China Biological Medicine Database (CBM-disc 1979 to 2008), China National Knowledge Infrastructure (CNKI 1994 to December 2008). RESULTS: The occurrence of intracranial artery stenosis was more frequent than that of extracranial artery in the Chinese population. TCD, Doppler ultrasound, CTA, MRA and DSA techniques are established to examine intracranial and extracranial atherosclerotic stenosis in China. Evidence-based treatments and CAS are more commonly applied in patients with cerebrovascular stenosis in China. However, the development of carotid endoarterectomy (CEA) is limited in Chinese communities. The risks of cerebral atherosclerotic stenosis include age, hypertension, diabetes mellitus, dyslipidemia, smoking and metabolic syndrome. CONCLUSIONS: Further studies are needed to focus on the intracranial atherosclerotic stenosis.


Subject(s)
Intracranial Arteriosclerosis/diagnosis , Intracranial Arteriosclerosis/epidemiology , China/epidemiology , Constriction, Pathologic/diagnosis , Constriction, Pathologic/epidemiology , Constriction, Pathologic/therapy , Endarterectomy, Carotid/adverse effects , Endarterectomy, Carotid/trends , Humans , Hypertension/diagnosis , Hypertension/epidemiology , Hypertension/therapy , Intracranial Arteriosclerosis/therapy , Risk Factors , Stroke/diagnosis , Stroke/epidemiology , Stroke/etiology , Treatment Outcome , Vascular Surgical Procedures/adverse effects , Vascular Surgical Procedures/trends
17.
Opt Express ; 22(19): 23473-9, 2014 Sep 22.
Article in English | MEDLINE | ID: mdl-25321816

ABSTRACT

The spontaneous emission of colloidal CdSe/ZnS quantum dots (CQDs) modified by the hybrid plasmonic-photonic crystal is reported in this paper. By using a spin coater, the spatial overlap between CQDs and the surface resonance modes in this quasi-2D crystal slab is achieved. In this case, the coupling efficiency of them is enhanced greatly and most excited CQDs radiate through the surface modes. Consequently, despite the low refractive index contrast of our hybrid structure, the directionality of spontaneous emission, increased radiative probability and narrowed full width at half maximum of emission peak are all clearly observed by our home-made microscopic angle-resolved spectroscopy and time-resolved photoluminescence system. Our results manifest that the quasi-2D hybrid plasmonic-photonic crystal is an ideal candidate to tailor the radiative properties of CdSe/ZnS CQDs, which might be significant for the applications of light emitting devices.


Subject(s)
Photons , Quantum Dots , Refractometry/instrumentation , Surface Plasmon Resonance/instrumentation , Equipment Design , Materials Testing
18.
Opt Express ; 22(12): 14212-20, 2014 Jun 16.
Article in English | MEDLINE | ID: mdl-24977518

ABSTRACT

Second-order nonlinear optical susceptibilities for second harmonic generation (SHG) associated with intersubband transitions in GaN/AlGaN single quantum well and step quantum well have been studied theoretically by solving Schrödinger and Poisson equations self-consistently. The calculated results suggest that due to the very large polarization-induced field in the quantum well, the potential profile becomes asymmetrical, leading to large second-order susceptibilities. A high value about 4 × 10-7 m/V can be obtained in single quantum well structure. Furthermore, by adopting step quantum well structure to increase the asymmetry degree of the potential profile and manipulate the energy levels for double-resonance, a significant enhancement of second-order susceptibility can occur in step quantum well. Specifically, the susceptibility can be as large as 4 × 10-6 m/V with structure optimization, about an order of magnitude greater than that in single quantum well. The results indicate that nonlinear optical elements based on GaN/AlGaN step quantum wells are very promising for SHG in a wide range of wavelengths from telecommunication to mid-infrared, especially effective in longer wavelength.

19.
Tech Coloproctol ; 18(8): 693-8, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24500725

ABSTRACT

BACKGROUND: Although surgery is the gold standard treatment for anal fissure, the main concern remains its side effects and complications. Botulinum toxin injection and lateral internal sphincterotomy are technical options for patients suffering from chronic anal fissure. However, little is known about the efficacy of these two techniques. The aim of this meta-analysis was to compare the outcomes of botulinum toxin injection versus lateral internal sphincterotomy for chronic anal fissure. METHODS: Original studies in English were searched from the MEDLINE database, PubMed, Web of Science, and the Cochrane Library database. Randomized control trials that compared botulinum toxin injection with lateral internal sphincterotomy were identified. Data were independently extracted for each study, and a meta-analysis was performed using fixed and random effects models. RESULTS: Four hundred and eighty-nine patients from seven trials met the inclusion criteria. Patients undergoing lateral internal sphincterotomy had a higher-healing and incontinence rate. No statistically significant differences were noted in total complications between botulinum toxin injection and lateral internal sphincterotomy. Patients treated with lateral internal sphincterotomy had a significantly lower recurrence rate than the patients treated with botulinum toxin injection. CONCLUSIONS: Our meta-analysis shows that lateral internal sphincterotomy was superior to botulinum toxin injection in terms of healing rate and lower recurrence rate. Botox, however, is safe associated with a lower rate of incontinence and could be used in certain situations. Further studies with a long-term follow-up are required to confirm our observations.


Subject(s)
Anal Canal/surgery , Botulinum Toxins, Type A/administration & dosage , Digestive System Surgical Procedures/methods , Fissure in Ano/therapy , Randomized Controlled Trials as Topic , Acetylcholine Release Inhibitors/administration & dosage , Chronic Disease , Humans , Treatment Outcome
20.
Plant Dis ; 98(10): 1433, 2014 Oct.
Article in English | MEDLINE | ID: mdl-30703961

ABSTRACT

Ginseng (Panax ginseng) is a perennial plant belonging to the genus Panax of the family Araliaceae, and it is a precious traditional Chinese medicine with immunity-enhancing, anti-tumor, anti-atherosclerosis, and other functions. Jilin Province, China, is the world's largest ginseng cultivation area, accounting for about 70% of global production. The root rots of ginseng caused by Fusarium spp. are one of the most serious threats to ginseng production. Seriously infected ginseng roots are not marketable, leading to enormous losses. The canopy of infected ginseng plants exhibit symptoms of red or yellow leaves from lower to upper during early plant development and growth, wither and wilt in the later stages, and lastly die. All parts of the root can be infected; brown or black lesions were mainly formed on surface and expanded gradually, and mature lesions are gray-brown. Samples of 208 Fusarium rotted roots (cv. landrace damaya) from Ji'an city (126°18' E, 41°12' N) and Dunhua city (128°23' E, 43°36' N) of Jilin Province were collected from April to September, 2012. Small tissue pieces were placed on potato dextrose agar (PDA), and all isolates were purified from single spore cultured at the condition of 25°C, 12-h/12-h light-dark cycle. Among the obtained purified 518 isolates, 10 isolates were different from the others. Colonies of the 10 isolates grew rapidly and produced profuse aerial mycelium with carmine red undersurface. When cultured on carnation leaf-piece agar (CLA), macroconidia were stout, thick-walled, apical and basal cells curved, usually 4 to 5 septa, 23.9 to 41.2 × 5.2 to 7.3 µm, but did not produce microconidia. Abundant chlamydospores were produced from mycelium or spores, singly or in chains. According to the morphological characteristics, all 10 isolates were consistent with the descriptions of F. cerealis (1). Further, identity of all isolates was confirmed by sequencing the partial rDNA internal transcribed spacer (ITS), translation elongation factor (TEF-1α) gene (3) and putative reductase (RED) gene (2). The sequences of all 10 isolates were homologous and BLAST analysis of the submitted sequences (KF530831, KF530830, and KF530829) showed 100% identity to the sequences (DQ459869, AF212464, and EF428900) of F. cerealis in the NCBI and the FUSARIUM-ID databases. As a result, 10 isolates of Fusarium spp. were identified as F. cerealis. Pathogenicity was tested by inoculating ginseng root in vitro and healthy plants in a greenhouse. The surface of healthy ginseng roots were washed with water and disinfested in 70% alcohol for 3 min and planted in flowerpots with sterilized soil and sorghum grain infested with each isolate and incubated in greenhouse (20 to 25°C). Five ginseng roots and five healthy plants were inoculated with agar cake and sterilized sorghum seed as controls. Root rots similar to the naturally symptoms were observed on inoculated ginseng roots in vitro and healthy plants after 3 days and 21 days, respectively, but no root rots developed on the controls. The pathogens were successfully re-isolated and were are identical to those of the originals. To our knowledge, this is the first report of F. cerealis causing root rot on ginseng in China. References: (1) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Publishing, Ames, IA, 2006. (2) K. O'Donnell et al. Proc. Nat. Acad. Sci. 97:7905, 2000. (3) K. O'Donnell et al. Mycologia 92:919, 2000.

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