This paper first presents a stochastic structural model to describe the random geometrical features of rock and soil aggregates. The stochastic structural model uses mixture ratio, rock size and rock shape to construc...This paper first presents a stochastic structural model to describe the random geometrical features of rock and soil aggregates. The stochastic structural model uses mixture ratio, rock size and rock shape to construct the microstructures of aggregates, and introduces two types of structural elements (block element and jointed element) and three types of material elements (rock element, soil element, and weaker jointed element) for this microstructure. Then, continuum-based discrete element method is used to study the deformation and failure mechanism of rock and soil aggregate through a series of loading tests. It is found that the stress-strain curve of rock and soil aggregates is nonlinear, and the failure is usually initialized from weaker jointed elements. Finally, some factors such as mixture ratio, rock size and rock shape are studied in detail. The numerical results are in good agreement with in situ test. Therefore, current model is effective for simulating the mechanical behaviors of rock and soil aggregates.展开更多
Bulk Fe-30Ni alloy melt was nudercooled up to 337K by combining the glass fluxing technique with superheating-cooling cycle. Grain refinement at low undercoolings was observed in the experiment in addition to that at ...Bulk Fe-30Ni alloy melt was nudercooled up to 337K by combining the glass fluxing technique with superheating-cooling cycle. Grain refinement at low undercoolings was observed in the experiment in addition to that at high undercoolings. The current grain refinement mechanisms were examined, and it is concluded that the refined gains are all developed from dendrites, however the grain refinement at low undercoolings is due to chemical superheating, while that at high undercoolings due to rapid solidification contruction.展开更多
The epidemiological characteristics and etiology of botulisin in China, as well as the distribution of different types of Clustridium bolulinum in China; are described.Through 1989, 15 provinces and autonomous region... The epidemiological characteristics and etiology of botulisin in China, as well as the distribution of different types of Clustridium bolulinum in China; are described.Through 1989, 15 provinces and autonomous regions reported the occurrence of botulism.There were 2861 cases involved in 745 outbreaks.Among the cases 421 died, with a case fatality of 14.7%.The main epidemiological characteristics of botulism in China are: (i) the major foods causing botulism are homemade fermented bean products which accounted for 62.6% of the cases; (ii) the incubation period is longer (3 h-54 days) than that described in the western literature (mostly 2-7 days); (iii) the peak occurrence is from February to May; (iv) the progression of symptoms and signs is slower than that of western cases.All types of C.bolulinum.with the exception of type G, have been found in China.The distribution of various types of C.botnlinum is significantly different between southern and northern China; this is related to the latitude and is correlated with the prevalence of this disease.Most of the botulism outbreaks occurred above 30° north latitude in northern China and outbreaks rarely occurred below 30° north latitude.Nationwide surveys showed that the average detection rate of C bolulinum spores in soil and foods in the northern parts of China was 14.8%.while it was only 2.5% in the south.C.bolulinum types A, B, E.and F, which are involved in human botulism, were frequently found in the North, while types C and D, which are involved only in animal intoxication, were found more frequently in the south. 1990 Academic Press.Inc.展开更多
With the aid of FE （finite element） code MSC.Superform 2005, 2-D coupled thermo-mechanical simulation of center-crack occurrence in round billet during 2-roll rotary rolling process was presented using Oyane ductile...With the aid of FE （finite element） code MSC.Superform 2005, 2-D coupled thermo-mechanical simulation of center-crack occurrence in round billet during 2-roll rotary rolling process was presented using Oyane ductile fracture criteria. A simple modeling is put forward based on the spiral motion of the workpiece as an essential characteristic in movement. The influence of the feed angle and the entry cone angle of the main roll on the process was taken into account in the modeling. The soundness for simplifying the 3-D rotary rolling into a 2-D problem was discussed. By adopting the parameters of Diescher piercer in 140mm mandrel mill of Bao Steel, the distribution and development of strain/stress were analyzed, and the eigen value of ductile fracture as well. The critical percentage of diameter reduction was obtained from the simulation. The result showed a good agreement with the experimental value, and therefore was of widely guiding significance to the practical process for rationally formulating the deformation parameters of steel tube piercing.展开更多
Aluminum-doped zinc oxide (AZO) thin films were deposited on sapphire (002) and glass substrates by two different sputtering techniques radio frequency magnetron cosputtering of AZO and ZnO targets and sputtering of a...Aluminum-doped zinc oxide (AZO) thin films were deposited on sapphire (002) and glass substrates by two different sputtering techniques radio frequency magnetron cosputtering of AZO and ZnO targets and sputtering of an AZO target. The dependence of the photoluminescence (PL) and transmittance properties of the AZO films deposited by cosputtering and sputtering on the AZO/ZnO target power ratio, R and the O2/Ar flow ratio, r were investigated, respectively. Only a deep level emission peak appears in the PL spectra of cosputtered AZO films whereas both UV emission and deep level emission peaks are observed in the PL spectra of sputtered AZO films. The absorption edges in the transmittance spectra of the AZO films shift to the lower wavelength region as R and r increase. Effects of crystallinity, surface roughness, PL on the transmittance of the AZO films were also explained using the X-ray diffraction (XRD), atomic force microscopy (AFM), and PL analysis results.展开更多
Objective: To investigate the origin, whether ocular or extraocular, of the short latency frontal potential (N15) reported by Todd et al. (2003) following vestibular stimulation. Methods: Fourteen subjects with low VE...Objective: To investigate the origin, whether ocular or extraocular, of the short latency frontal potential (N15) reported by Todd et al. (2003) following vestibular stimulation. Methods: Fourteen subjects with low VEMP thresholds (VT) and 9 patients with vestibular or ocular disorders were stimulated at the mastoid with bone-conducted tone bursts (500 Hz, 8 ms) above vestibular threshold, using a B71 bone vibrator. Surface potentials were recorded from Fpz and around the eyes and referred to linked earlobes. Results: The N15 was present at Fpz,but was largest around the eyes (mean amplitude 2.6 μV, peak latency 13.4 ms, with stimulation at +18 dB above threshold) and was generally in phase above and below the eyes. The response was vestibular-dependent and modulated by alteration of gaze direction. The potentials were delayed in a patient with Miller Fisher syndrome and were larger in patients with superior canal dehiscence than in controls. Conclusions: We report a new vestibular-evoked extraocular potential. Its properties are not consistent with an eye movement. It is likely to be produced, mainly or exclusively, by synchronous activity in extraocular muscles (i.e. a myogenic potential). Significance: Vestibularevoked extraocular potentials extend the range of vestibular pathways that can be assessed electrophysiologically, and may be a useful additional test of vestibular function.展开更多
Context: Cardiogenic shock remains the major cause of death for patients hospitalized with acute myocardial infarction(MI). Although survival in patients with cardiogenic shock complicating acute MI has been shown to ...Context: Cardiogenic shock remains the major cause of death for patients hospitalized with acute myocardial infarction(MI). Although survival in patients with cardiogenic shock complicating acute MI has been shown to be significantly higher at 1 year in those receiving early revascularization vs initial medical stabilization, data demonstrating long-term survival are lacking. Objective: To determine if early revascularization affects long-term survival of patients with cardiogenic shock complicating acute MI. Design, Setting, and Patients: The Should We Emergently Revascularize Occluded Coronaries for Cardiogenic Shock(SHOCK) trial, an international randomized clinical trial enrolling 302 patients from April 1993 through November 1998 with acute myocardial infarction complicated by cardiogenic shock(mean[SD] age at randomization, 66[11] years); long-term follow-up of vital status, conducted annually until 2005, ranged from 1 to 11 years(median for survivors, 6 years). Main Outcome Measures: All-cause mortality during long-term follow-up. Results: The group difference in survival of 13 absolute percentage points at 1 year favoring those assigned to early revascularization remained stable at 3 and 6 years(13.1%and 13.2%, respectively; hazard ratio[HR], 0.74; 95%confidence interval[CI], 0.57-0.97; log-rank P=.03). At 6 years, overall survival rates were 32.8%and 19.6%in the early revascularization and initial medical stabilization groups, respectively. Among the 143 hospital survivors, a group difference in survival also was observed(HR, 0.59; 95%CI, 0.36-0.95; P=.03). The 6-year survival rates for the hospital survivors were 62.4%vs 44.4%for the early revascularization and initial medical stabilization groups, respectively, with annualized death rates of 8.3%vs 14.3%and, for the 1-year survivors, 8.0%vs 10.7%. There was no significant interaction between any subgroup and treatment effect. Conclusions: In this randomized trial, almost two thirds of hospital survivors with cardiogenic shock who were treated with earl展开更多
Objective: To investigate the heterogeneity of idiopathic Parkinson’s disease (PD) in a data driven manner among a cohort of patients in the early clinical s tages of the disease meeting established diagnostic criter...Objective: To investigate the heterogeneity of idiopathic Parkinson’s disease (PD) in a data driven manner among a cohort of patients in the early clinical s tages of the disease meeting established diagnostic criteria. Methods: Data on d emographic,motor, mood, and cognitive measures were collected from 120 consecuti ve patients in the early stages of PD (Hoehn and YahrI-III) attending a special ist PD research clinic. Statistical cluster analysis of the data allowed the exi stence of the patient subgroups generated to be explored. Results: The analysis revealed four main subgroups: (a) patients with a younger disease onset; (b) a t remor dominant subgroup of patients; (c) a nontremor dominant subgroup with sign ificant levels of cognitive impairment and mild depression; and (d) a subgroup w ith rapid disease progression but no cognitive impairment. Conclusions:This stud y complements and extends previous research by using a data driven approach to d efine the clinical heterogeneity of early PD. The approach adopted in this study for the identifi cation of subgroups of patients within Parkinson’s disease ha s important implications for generating testable hypotheses on defining the heterogeneity of this common co ndition and its aetiopathological basis and thus its treatment.展开更多
<abstract>Abstract Aim: To evaluate the degree of corporal fibrosis in rats with cadaveric pericardium or vein as grafting materials for tunica albuginea substitution. Materials and methods: Thirty male Sprague-...<abstract>Abstract Aim: To evaluate the degree of corporal fibrosis in rats with cadaveric pericardium or vein as grafting materials for tunica albuginea substitution. Materials and methods: Thirty male Sprague-Dawley rats (300 g-325 g) were divided at random into 3 groups of 10 animals each: group 1 was the sham-operated controls and groups 2 and 3 underwent wedge excision of tunica albuginea and replacement with cadaveric pericardium and vein grafts, respectively. Four months later, rats were sacrificed and the penis removed to assess the degree of fibrosis using RT PCR technique for TGP-β1 mRNA expression. The tissues were fixed in 10 % formalin, paraffin-embedded and stained with Masson's trichrome and Verhoff's van Giesen for collagen and elastic fibers. Results: Four months after grafting, there was minimal fibrosis surrounding the patch in the vein graft rats and moderate fibrosis in the pericardial graft rats. The degree of penile fibrosis in the pericardial graft rats was significantly higher than that in the controls (P<0.01), but in the vein graft rats it was not significantly different from that of the controls (P>0.05). Conclusion: The degree of penile fibrosis of cadaveric pericardial graft was significantly higher than that of the control group, while in the vein graft group it was comparable to the latter. The authors believe that the vein graft may be a more ideal substance to be used as the tunica albuginea substitute than the pericardial graft in the surgical treatment of Peyronie's disease.展开更多
A new steel matrix wear resistant composite reinforced by in situ granular eutectics can be obtained by modifying with a Si-Ce-Ti compound in the steel melt. The result indicates that the in situ granular eutectic is...A new steel matrix wear resistant composite reinforced by in situ granular eutectics can be obtained by modifying with a Si-Ce-Ti compound in the steel melt. The result indicates that the in situ granular eutectic is a pseudo-eutectic of austenite and (Fe,Mn)3C, which is formed between austenite dendrites during solidification due to the segregation of C and Mn impelled by modifying elements. The quantity of in situ granular eutectic reaches up to 8%-12% and its grain size is in the range from 10um to 20um. The austenite steel matrix wear resistant composite reinforced by in situ granular eutectic (abbreviated AGE composite) and austenite-bainite steel mains wear resistant composite reinforced by in situ granular eutectic (abbreviated ABGE composite) are obtained in the as-cast state and by air hardening, respectively. The wear resistance of the AGE and ABGE composites can be more greatly increased than that of their matrix steels under low and medium impact working condition.展开更多
The CASTRIP* process produces a range of high strength Ultra-thin Cast Strip (UCS) products (380-550 MPa) in thicknesses between 0.9 mm and 1.5 mm, which is very challenging to produce via conventional hot and cold ro...The CASTRIP* process produces a range of high strength Ultra-thin Cast Strip (UCS) products (380-550 MPa) in thicknesses between 0.9 mm and 1.5 mm, which is very challenging to produce via conventional hot and cold rolled processing routes. The twin roll CASTRIP process fully exploits the hardenability and strengthening potential of Nb in a low C-Mn-Nb-V microalloyed steel type. Significant microstructural strengthening from solute Nb was obtained, even at low microalloying levels, as well as modest Mn additions, through enhancing the hardenability and further strengthening was obtained in coated products by exploiting age hardening during processing on a continuous hot dip galvanising line. Atom probe tomography and TEM determined that Nb was retained in solid solution and subsequent age hardening resulted from the formation of Nb and V rich nanosized particles. Age hardening was achieved without loss of ductility producing galvanised strip with an excellent strength-ductility combination (Y.S. 】600 MPa, T.E. 】10%).展开更多
Objectives: To define optical coherence tomographic (OCT)-criteria for the diagnosis of a lamellar macular hole, and to increase understanding of lamellar hole pathogenesis by examining fine anatomic features using ul...Objectives: To define optical coherence tomographic (OCT)-criteria for the diagnosis of a lamellar macular hole, and to increase understanding of lamellar hole pathogenesis by examining fine anatomic features using ultrahigh-resolution optical coherence tomography (UHR OCT). Design: Retrospective observational case series. Participants: Nineteen eyes of 18 patients with lamellar holes were imaged with UHR OCT between 2002 and 2004. Methods: A UHR OCT system was developed for use in the ophthalmology clinic. All 6 UHR OCT images for each eye imaged were examined. Lamellar holes were diagnosed based on a characteristic OCT appearance. Criteria for the OCT diagnosis of a lamellar hole were as follows: (1) irregular foveal contour; (2) break in the inner fovea; (3) intraretinal split; and (4) intact foveal photoreceptors. From 1205 eyes of 664 patients imaged with UHR OCT, and retrospectively reviewed, 19 eyes of 18 patients were diagnosed with a lamellar hole based on these criteria. All 19 eyes were also imaged with standard resolution OCT. Their charts were retrospectively reviewed. Main Outcome Measures: Standard and ultrahigh-resolution OCT images. Results: On chart review, clinical diagnosis of a lamellar hole was made in only 7 of 19 eyes (37% ). Twelve of 19 eyes (63% ) had an epiretinal membrane (ERM) on clinical examination. Ten of 19 eyes (53% ) had a posterior vitreous detachment. On UHR OCT, 17 of 19 eyes (89% ) had ERMs. Eleven ERMs had an unusual thick appearance on UHR OCT. Due to poor visual acuity, 4 eyes underwent vitrectomy. Only 1 of 4 surgeries (25% ) was visually and anatomically successful. Another eye improved visually, but a lamellar hole persisted. One eye progressed to a full-thickness macular hole preoperatively, which reopened after surgery. One eye developed a full-thickness hole postoperatively. Conclusions: The diagnosis of a lamellar hole can be made based on OCT criteria, which could be applied to both standard and ultrahigh-resolution OCT. The increased resolution of UHR OCT sheds 展开更多
The beta-2-adrenergic receptor (β2-AR) has several single- nucleotide polymorphisms. These influence the functional response to adrenergic stimulation; genotypes homozygous for Gly16-Glu27 or Gly16-Gln27 alleles (Gly...The beta-2-adrenergic receptor (β2-AR) has several single- nucleotide polymorphisms. These influence the functional response to adrenergic stimulation; genotypes homozygous for Gly16-Glu27 or Gly16-Gln27 alleles (Gly16-Glu/Gln27 haplotypes) are associated with enhanced response, whereas genotypes homozygous for Arg16-Gln27 alleles (Arg16-Gln27) show a decreased response. We hypothesized that gene polymorphisms at the β2-AR may influence the hemodynamic response to propranolol in patients with cirrhosis. The β2-AR gene polymorphisms were determined by direct sequencing of the polymerase chain reaction (PCR) products in 48 patients with cirrhosis. All patients also had hepatic and systemic hemodynamic studies before and after propranolol administration. Prevalence of Gly16-Glu/Gln27 haplotypes was 29.1%, Arg16-Gln27 haplotype was 16.7%,and 54.2%were compound heterozygotes. Patients with cirrhosis with Gly16-Glu/Ghl27 haplotypes had a greater decrease in heart rate, cardiac index, and hepatic blood flow after propranolol administration than those with Arg16-Gln27 haplotype. However, the HVPG response to propranolol was similar in both groups, whereas estimated hepatic sinusoidal resistance increased significantly in Gly16-Glu/Gln27 haplotypes but not in Arg16-Gln27 (+27.1 ±17.8%vs -17.9 ±13.9%, P = .042), suggesting that unopposed vasoconstrictive activity at the intrahepatic circulation hinders the fall in HVPG despite enhanced hemodynamic response to propranolol in Gly16-Glu/Ghi27 haplotypes. In conclusion, β2-AR gene polymorphisms influence the response to beta-blockade. However, HVPG reduction cannot be predicted from polymorphism analysis. Patients with the Gly16-Glu/Gln27 haplotypesmay benefit from the association of hepatic vasodilators to propranolol therapy.展开更多
We have previously reported a limited but favorable experience with a novel sutureless technique for surgical management of postoperative pulmonary vein stenosis occurring after repair of total anomalous pulmonary ven...We have previously reported a limited but favorable experience with a novel sutureless technique for surgical management of postoperative pulmonary vein stenosis occurring after repair of total anomalous pulmonary venous drainage. Because this technique requires integrity of the retrocardiac space for hemostasis, extension of the technique to the primary repair of pulmonary vein anomalies requires evaluation. This analysis reviews our experiencewith the sutureless technique in patients with postrepair pulmonary vein stenosis, as well as our extension of the technique into primary repair of pulmonary vein anomalies. Retrospective univariable-multivariable analysis of all pulmonary vein stenosis procedures and sutureless pulmonary vein procedures over a 20-year period was performed. Cox proportional hazards modeling was used to identify variables associated with freedom from reoperation or death. Sixty patients underwent 73 procedures, with pulmonary vein stenosis present in 65 procedures. The sutureless technique was used in 40 procedures. Freedom from reoperation or death at 5 years after the initial procedure was 49%. Unadjusted freedom from reoperation or death was greater with the sutureless technique for patients with postrepair pulmonary vein stenosis(P=.04). By using multivariable analysis, a higher pulmonary vein stenosis score was associated with greater risk of reoperation or death. After adjustment, the sutureless repair was associated with a nonsignificant trend toward greater freedom from reoperation or death(P=.12). Despite the absence of retrocardiac adhesions, operative mortality was not increased with the sutureless technique(P=.64). Techniques to control bleeding(intrapleural hilar reapproximation)and improve exposure(inferior vena cava division)were identified. The sutureless technique for postrepair pulmonary vein stenosis is associated with encouraging midterm results. Extension of the indications for the technique to primary repair appears safe with the development of simple intraoperative ma展开更多
Transient laminar flows and pressure-wave propagation in pipes, commonly called as water hammer, have been analyzed. A pressure-wave equation and a linearized velocity equation were derived from the equations of mass ...Transient laminar flows and pressure-wave propagation in pipes, commonly called as water hammer, have been analyzed. A pressure-wave equation and a linearized velocity equation were derived from the equations of mass and momentum conservation. The waveform distortion due to viscous dissipation and elastic expansion of pipe wall was characterized by a dimensionless transmission number. The damping coefficients of pressure waves were found to be related to the roots of Bessel function. An exact solution of pressure-wave equation was obtained numerically. The relationship between the distortion of a traveling wave and transmission number was studied. The problem was also calculated with a general-purpose computer code, COMMIX, which solves exact mass conservation equation and Navier-Stokes equations. The computational results of the COMMIX code agreed well with the analytical solutions.展开更多
Creep behavior of γ-TiAl polysynthetically twinned (PST) crystals has been investigated at temperature between 700 and 800℃. The results show that the creep behavior of the crystals is strongly dependent on the angl...Creep behavior of γ-TiAl polysynthetically twinned (PST) crystals has been investigated at temperature between 700 and 800℃. The results show that the creep behavior of the crystals is strongly dependent on the angle between the lamellar boundaries and loading axis. The samples with the angle φ=45 deg. have the lowest creep resistance, while the samples with φ=0 deg., rather than φ=90 deg.,show the strongest creep resistance. The stress exponent and creep activation energy for the power law creep vary with the orientations of samples, which indicates that the creep mechanisms of the samples with different angle φ are quite different.The deformation substructure has been examined by transmission electron microscopy (TEM),which shows that both gliding, perhaps also climbing, of dislocations and twinning contribute to the creep deformation with some particular observation in the samples with φ=90 deg. in which rotation of the γ plates across a true twin boundary was observed, which indicates the deformation mechanism of the samples is different from the samples in other orientations.展开更多
文摘This paper first presents a stochastic structural model to describe the random geometrical features of rock and soil aggregates. The stochastic structural model uses mixture ratio, rock size and rock shape to construct the microstructures of aggregates, and introduces two types of structural elements (block element and jointed element) and three types of material elements (rock element, soil element, and weaker jointed element) for this microstructure. Then, continuum-based discrete element method is used to study the deformation and failure mechanism of rock and soil aggregate through a series of loading tests. It is found that the stress-strain curve of rock and soil aggregates is nonlinear, and the failure is usually initialized from weaker jointed elements. Finally, some factors such as mixture ratio, rock size and rock shape are studied in detail. The numerical results are in good agreement with in situ test. Therefore, current model is effective for simulating the mechanical behaviors of rock and soil aggregates.
文摘Bulk Fe-30Ni alloy melt was nudercooled up to 337K by combining the glass fluxing technique with superheating-cooling cycle. Grain refinement at low undercoolings was observed in the experiment in addition to that at high undercoolings. The current grain refinement mechanisms were examined, and it is concluded that the refined gains are all developed from dendrites, however the grain refinement at low undercoolings is due to chemical superheating, while that at high undercoolings due to rapid solidification contruction.
文摘 The epidemiological characteristics and etiology of botulisin in China, as well as the distribution of different types of Clustridium bolulinum in China; are described.Through 1989, 15 provinces and autonomous regions reported the occurrence of botulism.There were 2861 cases involved in 745 outbreaks.Among the cases 421 died, with a case fatality of 14.7%.The main epidemiological characteristics of botulism in China are: (i) the major foods causing botulism are homemade fermented bean products which accounted for 62.6% of the cases; (ii) the incubation period is longer (3 h-54 days) than that described in the western literature (mostly 2-7 days); (iii) the peak occurrence is from February to May; (iv) the progression of symptoms and signs is slower than that of western cases.All types of C.bolulinum.with the exception of type G, have been found in China.The distribution of various types of C.botnlinum is significantly different between southern and northern China; this is related to the latitude and is correlated with the prevalence of this disease.Most of the botulism outbreaks occurred above 30° north latitude in northern China and outbreaks rarely occurred below 30° north latitude.Nationwide surveys showed that the average detection rate of C bolulinum spores in soil and foods in the northern parts of China was 14.8%.while it was only 2.5% in the south.C.bolulinum types A, B, E.and F, which are involved in human botulism, were frequently found in the North, while types C and D, which are involved only in animal intoxication, were found more frequently in the south. 1990 Academic Press.Inc.
文摘With the aid of FE （finite element） code MSC.Superform 2005, 2-D coupled thermo-mechanical simulation of center-crack occurrence in round billet during 2-roll rotary rolling process was presented using Oyane ductile fracture criteria. A simple modeling is put forward based on the spiral motion of the workpiece as an essential characteristic in movement. The influence of the feed angle and the entry cone angle of the main roll on the process was taken into account in the modeling. The soundness for simplifying the 3-D rotary rolling into a 2-D problem was discussed. By adopting the parameters of Diescher piercer in 140mm mandrel mill of Bao Steel, the distribution and development of strain/stress were analyzed, and the eigen value of ductile fracture as well. The critical percentage of diameter reduction was obtained from the simulation. The result showed a good agreement with the experimental value, and therefore was of widely guiding significance to the practical process for rationally formulating the deformation parameters of steel tube piercing.
文摘Aluminum-doped zinc oxide (AZO) thin films were deposited on sapphire (002) and glass substrates by two different sputtering techniques radio frequency magnetron cosputtering of AZO and ZnO targets and sputtering of an AZO target. The dependence of the photoluminescence (PL) and transmittance properties of the AZO films deposited by cosputtering and sputtering on the AZO/ZnO target power ratio, R and the O2/Ar flow ratio, r were investigated, respectively. Only a deep level emission peak appears in the PL spectra of cosputtered AZO films whereas both UV emission and deep level emission peaks are observed in the PL spectra of sputtered AZO films. The absorption edges in the transmittance spectra of the AZO films shift to the lower wavelength region as R and r increase. Effects of crystallinity, surface roughness, PL on the transmittance of the AZO films were also explained using the X-ray diffraction (XRD), atomic force microscopy (AFM), and PL analysis results.
文摘Objective: To investigate the origin, whether ocular or extraocular, of the short latency frontal potential (N15) reported by Todd et al. (2003) following vestibular stimulation. Methods: Fourteen subjects with low VEMP thresholds (VT) and 9 patients with vestibular or ocular disorders were stimulated at the mastoid with bone-conducted tone bursts (500 Hz, 8 ms) above vestibular threshold, using a B71 bone vibrator. Surface potentials were recorded from Fpz and around the eyes and referred to linked earlobes. Results: The N15 was present at Fpz,but was largest around the eyes (mean amplitude 2.6 μV, peak latency 13.4 ms, with stimulation at +18 dB above threshold) and was generally in phase above and below the eyes. The response was vestibular-dependent and modulated by alteration of gaze direction. The potentials were delayed in a patient with Miller Fisher syndrome and were larger in patients with superior canal dehiscence than in controls. Conclusions: We report a new vestibular-evoked extraocular potential. Its properties are not consistent with an eye movement. It is likely to be produced, mainly or exclusively, by synchronous activity in extraocular muscles (i.e. a myogenic potential). Significance: Vestibularevoked extraocular potentials extend the range of vestibular pathways that can be assessed electrophysiologically, and may be a useful additional test of vestibular function.
文摘Context: Cardiogenic shock remains the major cause of death for patients hospitalized with acute myocardial infarction(MI). Although survival in patients with cardiogenic shock complicating acute MI has been shown to be significantly higher at 1 year in those receiving early revascularization vs initial medical stabilization, data demonstrating long-term survival are lacking. Objective: To determine if early revascularization affects long-term survival of patients with cardiogenic shock complicating acute MI. Design, Setting, and Patients: The Should We Emergently Revascularize Occluded Coronaries for Cardiogenic Shock(SHOCK) trial, an international randomized clinical trial enrolling 302 patients from April 1993 through November 1998 with acute myocardial infarction complicated by cardiogenic shock(mean[SD] age at randomization, 66[11] years); long-term follow-up of vital status, conducted annually until 2005, ranged from 1 to 11 years(median for survivors, 6 years). Main Outcome Measures: All-cause mortality during long-term follow-up. Results: The group difference in survival of 13 absolute percentage points at 1 year favoring those assigned to early revascularization remained stable at 3 and 6 years(13.1%and 13.2%, respectively; hazard ratio[HR], 0.74; 95%confidence interval[CI], 0.57-0.97; log-rank P=.03). At 6 years, overall survival rates were 32.8%and 19.6%in the early revascularization and initial medical stabilization groups, respectively. Among the 143 hospital survivors, a group difference in survival also was observed(HR, 0.59; 95%CI, 0.36-0.95; P=.03). The 6-year survival rates for the hospital survivors were 62.4%vs 44.4%for the early revascularization and initial medical stabilization groups, respectively, with annualized death rates of 8.3%vs 14.3%and, for the 1-year survivors, 8.0%vs 10.7%. There was no significant interaction between any subgroup and treatment effect. Conclusions: In this randomized trial, almost two thirds of hospital survivors with cardiogenic shock who were treated with earl
文摘Objective: To investigate the heterogeneity of idiopathic Parkinson’s disease (PD) in a data driven manner among a cohort of patients in the early clinical s tages of the disease meeting established diagnostic criteria. Methods: Data on d emographic,motor, mood, and cognitive measures were collected from 120 consecuti ve patients in the early stages of PD (Hoehn and YahrI-III) attending a special ist PD research clinic. Statistical cluster analysis of the data allowed the exi stence of the patient subgroups generated to be explored. Results: The analysis revealed four main subgroups: (a) patients with a younger disease onset; (b) a t remor dominant subgroup of patients; (c) a nontremor dominant subgroup with sign ificant levels of cognitive impairment and mild depression; and (d) a subgroup w ith rapid disease progression but no cognitive impairment. Conclusions:This stud y complements and extends previous research by using a data driven approach to d efine the clinical heterogeneity of early PD. The approach adopted in this study for the identifi cation of subgroups of patients within Parkinson’s disease ha s important implications for generating testable hypotheses on defining the heterogeneity of this common co ndition and its aetiopathological basis and thus its treatment.
文摘<abstract>Abstract Aim: To evaluate the degree of corporal fibrosis in rats with cadaveric pericardium or vein as grafting materials for tunica albuginea substitution. Materials and methods: Thirty male Sprague-Dawley rats (300 g-325 g) were divided at random into 3 groups of 10 animals each: group 1 was the sham-operated controls and groups 2 and 3 underwent wedge excision of tunica albuginea and replacement with cadaveric pericardium and vein grafts, respectively. Four months later, rats were sacrificed and the penis removed to assess the degree of fibrosis using RT PCR technique for TGP-β1 mRNA expression. The tissues were fixed in 10 % formalin, paraffin-embedded and stained with Masson's trichrome and Verhoff's van Giesen for collagen and elastic fibers. Results: Four months after grafting, there was minimal fibrosis surrounding the patch in the vein graft rats and moderate fibrosis in the pericardial graft rats. The degree of penile fibrosis in the pericardial graft rats was significantly higher than that in the controls (P<0.01), but in the vein graft rats it was not significantly different from that of the controls (P>0.05). Conclusion: The degree of penile fibrosis of cadaveric pericardial graft was significantly higher than that of the control group, while in the vein graft group it was comparable to the latter. The authors believe that the vein graft may be a more ideal substance to be used as the tunica albuginea substitute than the pericardial graft in the surgical treatment of Peyronie's disease.
基金Acknowledgements - This project was supported by the National Natural Science Foundation of China (Grant No.50001008).
文摘A new steel matrix wear resistant composite reinforced by in situ granular eutectics can be obtained by modifying with a Si-Ce-Ti compound in the steel melt. The result indicates that the in situ granular eutectic is a pseudo-eutectic of austenite and (Fe,Mn)3C, which is formed between austenite dendrites during solidification due to the segregation of C and Mn impelled by modifying elements. The quantity of in situ granular eutectic reaches up to 8%-12% and its grain size is in the range from 10um to 20um. The austenite steel matrix wear resistant composite reinforced by in situ granular eutectic (abbreviated AGE composite) and austenite-bainite steel mains wear resistant composite reinforced by in situ granular eutectic (abbreviated ABGE composite) are obtained in the as-cast state and by air hardening, respectively. The wear resistance of the AGE and ABGE composites can be more greatly increased than that of their matrix steels under low and medium impact working condition.
文摘The CASTRIP* process produces a range of high strength Ultra-thin Cast Strip (UCS) products (380-550 MPa) in thicknesses between 0.9 mm and 1.5 mm, which is very challenging to produce via conventional hot and cold rolled processing routes. The twin roll CASTRIP process fully exploits the hardenability and strengthening potential of Nb in a low C-Mn-Nb-V microalloyed steel type. Significant microstructural strengthening from solute Nb was obtained, even at low microalloying levels, as well as modest Mn additions, through enhancing the hardenability and further strengthening was obtained in coated products by exploiting age hardening during processing on a continuous hot dip galvanising line. Atom probe tomography and TEM determined that Nb was retained in solid solution and subsequent age hardening resulted from the formation of Nb and V rich nanosized particles. Age hardening was achieved without loss of ductility producing galvanised strip with an excellent strength-ductility combination (Y.S. 】600 MPa, T.E. 】10%).
文摘Objectives: To define optical coherence tomographic (OCT)-criteria for the diagnosis of a lamellar macular hole, and to increase understanding of lamellar hole pathogenesis by examining fine anatomic features using ultrahigh-resolution optical coherence tomography (UHR OCT). Design: Retrospective observational case series. Participants: Nineteen eyes of 18 patients with lamellar holes were imaged with UHR OCT between 2002 and 2004. Methods: A UHR OCT system was developed for use in the ophthalmology clinic. All 6 UHR OCT images for each eye imaged were examined. Lamellar holes were diagnosed based on a characteristic OCT appearance. Criteria for the OCT diagnosis of a lamellar hole were as follows: (1) irregular foveal contour; (2) break in the inner fovea; (3) intraretinal split; and (4) intact foveal photoreceptors. From 1205 eyes of 664 patients imaged with UHR OCT, and retrospectively reviewed, 19 eyes of 18 patients were diagnosed with a lamellar hole based on these criteria. All 19 eyes were also imaged with standard resolution OCT. Their charts were retrospectively reviewed. Main Outcome Measures: Standard and ultrahigh-resolution OCT images. Results: On chart review, clinical diagnosis of a lamellar hole was made in only 7 of 19 eyes (37% ). Twelve of 19 eyes (63% ) had an epiretinal membrane (ERM) on clinical examination. Ten of 19 eyes (53% ) had a posterior vitreous detachment. On UHR OCT, 17 of 19 eyes (89% ) had ERMs. Eleven ERMs had an unusual thick appearance on UHR OCT. Due to poor visual acuity, 4 eyes underwent vitrectomy. Only 1 of 4 surgeries (25% ) was visually and anatomically successful. Another eye improved visually, but a lamellar hole persisted. One eye progressed to a full-thickness macular hole preoperatively, which reopened after surgery. One eye developed a full-thickness hole postoperatively. Conclusions: The diagnosis of a lamellar hole can be made based on OCT criteria, which could be applied to both standard and ultrahigh-resolution OCT. The increased resolution of UHR OCT sheds
文摘The beta-2-adrenergic receptor (β2-AR) has several single- nucleotide polymorphisms. These influence the functional response to adrenergic stimulation; genotypes homozygous for Gly16-Glu27 or Gly16-Gln27 alleles (Gly16-Glu/Gln27 haplotypes) are associated with enhanced response, whereas genotypes homozygous for Arg16-Gln27 alleles (Arg16-Gln27) show a decreased response. We hypothesized that gene polymorphisms at the β2-AR may influence the hemodynamic response to propranolol in patients with cirrhosis. The β2-AR gene polymorphisms were determined by direct sequencing of the polymerase chain reaction (PCR) products in 48 patients with cirrhosis. All patients also had hepatic and systemic hemodynamic studies before and after propranolol administration. Prevalence of Gly16-Glu/Gln27 haplotypes was 29.1%, Arg16-Gln27 haplotype was 16.7%,and 54.2%were compound heterozygotes. Patients with cirrhosis with Gly16-Glu/Ghl27 haplotypes had a greater decrease in heart rate, cardiac index, and hepatic blood flow after propranolol administration than those with Arg16-Gln27 haplotype. However, the HVPG response to propranolol was similar in both groups, whereas estimated hepatic sinusoidal resistance increased significantly in Gly16-Glu/Gln27 haplotypes but not in Arg16-Gln27 (+27.1 ±17.8%vs -17.9 ±13.9%, P = .042), suggesting that unopposed vasoconstrictive activity at the intrahepatic circulation hinders the fall in HVPG despite enhanced hemodynamic response to propranolol in Gly16-Glu/Ghi27 haplotypes. In conclusion, β2-AR gene polymorphisms influence the response to beta-blockade. However, HVPG reduction cannot be predicted from polymorphism analysis. Patients with the Gly16-Glu/Gln27 haplotypesmay benefit from the association of hepatic vasodilators to propranolol therapy.
文摘We have previously reported a limited but favorable experience with a novel sutureless technique for surgical management of postoperative pulmonary vein stenosis occurring after repair of total anomalous pulmonary venous drainage. Because this technique requires integrity of the retrocardiac space for hemostasis, extension of the technique to the primary repair of pulmonary vein anomalies requires evaluation. This analysis reviews our experiencewith the sutureless technique in patients with postrepair pulmonary vein stenosis, as well as our extension of the technique into primary repair of pulmonary vein anomalies. Retrospective univariable-multivariable analysis of all pulmonary vein stenosis procedures and sutureless pulmonary vein procedures over a 20-year period was performed. Cox proportional hazards modeling was used to identify variables associated with freedom from reoperation or death. Sixty patients underwent 73 procedures, with pulmonary vein stenosis present in 65 procedures. The sutureless technique was used in 40 procedures. Freedom from reoperation or death at 5 years after the initial procedure was 49%. Unadjusted freedom from reoperation or death was greater with the sutureless technique for patients with postrepair pulmonary vein stenosis(P=.04). By using multivariable analysis, a higher pulmonary vein stenosis score was associated with greater risk of reoperation or death. After adjustment, the sutureless repair was associated with a nonsignificant trend toward greater freedom from reoperation or death(P=.12). Despite the absence of retrocardiac adhesions, operative mortality was not increased with the sutureless technique(P=.64). Techniques to control bleeding(intrapleural hilar reapproximation)and improve exposure(inferior vena cava division)were identified. The sutureless technique for postrepair pulmonary vein stenosis is associated with encouraging midterm results. Extension of the indications for the technique to primary repair appears safe with the development of simple intraoperative ma
文摘Transient laminar flows and pressure-wave propagation in pipes, commonly called as water hammer, have been analyzed. A pressure-wave equation and a linearized velocity equation were derived from the equations of mass and momentum conservation. The waveform distortion due to viscous dissipation and elastic expansion of pipe wall was characterized by a dimensionless transmission number. The damping coefficients of pressure waves were found to be related to the roots of Bessel function. An exact solution of pressure-wave equation was obtained numerically. The relationship between the distortion of a traveling wave and transmission number was studied. The problem was also calculated with a general-purpose computer code, COMMIX, which solves exact mass conservation equation and Navier-Stokes equations. The computational results of the COMMIX code agreed well with the analytical solutions.
文摘Creep behavior of γ-TiAl polysynthetically twinned (PST) crystals has been investigated at temperature between 700 and 800℃. The results show that the creep behavior of the crystals is strongly dependent on the angle between the lamellar boundaries and loading axis. The samples with the angle φ=45 deg. have the lowest creep resistance, while the samples with φ=0 deg., rather than φ=90 deg.,show the strongest creep resistance. The stress exponent and creep activation energy for the power law creep vary with the orientations of samples, which indicates that the creep mechanisms of the samples with different angle φ are quite different.The deformation substructure has been examined by transmission electron microscopy (TEM),which shows that both gliding, perhaps also climbing, of dislocations and twinning contribute to the creep deformation with some particular observation in the samples with φ=90 deg. in which rotation of the γ plates across a true twin boundary was observed, which indicates the deformation mechanism of the samples is different from the samples in other orientations.
