In this paper,we present a cross-constrained variational method to study the Cauchy problem of the nonlinear Klein-Gordon equations with critical nonlinearity in two space dimensions.By constructing a type of cross-constrained variational problem and establishing so-called cross-invariant manifolds of the evolution flow,we establish a sharp threshold of global existence and blowup of it.Furthermore,we answer the question: How small are the initial data if the solution exists globally.
Background: Psoriasis of the hands and feet is a chronic disease which is often resistant to the usual topical therapies. It has considerable morbidity and seriously affects the quality of life of patients. Objective: We sought to prospectively evaluate the efficacy and safety of pulsed dye laser (PDL) treatment of psoriasis of the hands and feet. Methods: In all, 41 patients with therapy- resistant psoriasis of the hands and feet were treated once every 4 to 6 weeks with PDL at 585- nm wavelength, 450- microsecond pulse duration, 7- mm spot diameter, and 5- to 6.5 Jcm2 fluence. Calcipotriol ointment and salicylic acid 5% to 10% ointment were used as keratolytic agents. Treatment efficacy was evaluated by blinded comparison of photographs of the lesions taken before and after PDL treatment in each patient. Results: A good to very good improvement in the lesions was observed in 76% of the patients after treatment. An average duration of remission was 11 months. Side effects were transient purpura, moderate discomfort during the treatment, transient hyperpigmentation or hypopigmentation, and incidental transient crustae. Limitations: This was an open prospective study with a limited number of patients who were concomitantly treated with calcipotriol and salicylic acid ointment. Patients with photointolerance, on medication with phototoxic or photoallergic drugs, and with widespread psoriasis were excluded. Conclusions: Concomitant treatment with PDL and topical calcipotriol, salicylic acid, or both was a satisfactory modality for treating psoriasis of the hands and feet. There was a subjective improvement in the symptoms and quality of life in all patients.
The effect of pressure and temperature on the stability of all-silicon ZSM-5 zeolite is re- ported for the first time.It has been found that ZSM-5 zeolite is directly transformed into ZSM-11 zeolite un- der the pressure of 4.0 GPa at room temperature and that this transformation is irreversible.ZSM-5 zeolite is transformed into β-quartz by high pressure quenching,which is obtained for the first time at room temper- ature,and coesite under high pressure and high temperature.
Background:An elevated plasma homocysteine level is an established risk factor for cardiovascular disease.Vitamin B12 plays a key role in homocysteine metabolism and could be the main factor in causing cardiovascular disease as well.Objectives:The aim of this study was to assess whether vitamin B12 deficiency or hyperhomocysteinaemia is associated with recurrent cardiovascular events.Methods:Overall,211 patients discharged alive from our Coronary Care Unit were recruited from February till May 1998.Serum vitamin B12 and plasma homocysteine levels were measured in fasting blood samples.Patient characteristics,medical information and cardiovascular risk factors were assessed from medical files.Patients were followed for 5 years and the prevalence of cardiovascular mortality and morbidity was collected.Results:In the follow-up period of 810 person-years,48(21%)of the patients experienced a nonfatal recurrent cardiovascular event and another 14(7%)died of a cardiovascular cause.Among those with ischaemic heart disease at discharge,no difference in survival was found between the patients with a low( 250 pmol/l)or a high vitamin B12 level(p=0.21).In patients with hyperhomocysteinaemia(16 μ mol/l),an increased risk of a recurrent cardiovascular event(p=0.05)in comparison to those with normal plasma homocysteine levels was proven(adjusted hazard ratio of 2.22(95% CI:1.40-3.04)).Conclusions:In conclusion,high plasma homocysteine concentration,but not a low serum vitamin B12 concentration,increases the risk of cardiovascular morbidity and mortality in patients with ischaemic heart disease.
The effect of thermal cycling on the tetragonal(t)to monoclinic(m)transformation in hot pressed zirconia doped with 2mol% yttria has been investigated using high temperature X-ray diffractometer and transmission electron microscope,Results show that with the increase of the number of thermal cycling,the starting point of t→m transformation(M_s)gradually increases while the ending point of t→m transformation(M_f)remains relatlvely unchanged,the relative amount of monoclinic phase also increases,From the viewpoint of thermodynamics of transformation,the experimental results have been rationalized.
In this research,the centrifugal compressor of a turbocharger is investigated experimentally and numerically. Performance characteristics of the compressor were obtained experimentally by measurements of rotor speed and flow parameters at the inlet and outlet of the compressor.Three dimensional flow field in the impeller and dif- fuser was analyzed numerically using a full Navier-Stokes program with SST turbulence model.The performance characteristics of the compressor were obtained numerically,which were then compared with the experimental results.The comparison shows good agreement. Furthermore,the effect of area ratio and tip clearance on the performance parameters and flow field was stud- ied numerically.The impeller area ratio was changed by cutting the impeller exit axial width from an initial value of 4.1 mm to a final value of 5.1 mm,resulting in an area ratio from 0.792 to 0.965.For the rotor with exit axial width of 4.6 mm,performance was investigated for tip clearance of 0.0,0.5 and 1.0 mm.Results of this simula- tion at design point showed that the compressor pressure ratio peaked at an area ratio of 0.792 while the effi- ciency peaked at a higher value of area ratio of 0.878.Also the increment of the tip clearance from 0 to 1 mm re- sulted in 20 percent efficiency decrease.
A major bottleneck of crop breeding is the narrow genetic base of cultivated species.It is a must to introgress new beneficial alleles from wild germplasm.Due to crossing barrier and linkage drag,conventional breeding isn't effective in use of these beneficial alleles.The rapid development of genomics enables the isolation of a number of plant genes in an easy way.Cisgenesis is a genetic modification approach to quickly transfer beneficial alleles from crossable species into elite cultivars.This approach will not only speed up breeding process but also avoid linkage drag.As the origins of target genes by cisgenesis and conventional breeding are the same,cultivars released by these two approaches are same in safety.If regulators could treat cisgenic plants the same as conventionally bred plants,cisgenesis will become an effective tool of crop improvement in use of wild germplasm.
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