Bianchi Type-II, VIII &IX Perfect Fluid Cosmological Models in Brans Dicke Theory of Gravitation

Field equations in the presence of perfect fluid distribution are obtained in a scalar tensor theory of gravitation proposed by Brans and Dicke[1] with the aid of Bianchi type-II, VIII & IX metrics. Exact prefect fluid Bianchi type- IX cosmological model is presented since other models doesn’t exist in Brans-Dicke scalar tensor theory of gravitation. Some physical properties of the model are also discussed.

LRS Bianchi Type-II Inflationary Universe with Massless Scalar Field and Time Varying Λ

The locally rotationally symmetric(LRS)Bianchi type-II inflationary cosmological model is investigated for massless scalar field with flat potential and time varyingΛ.To obtain the deterministic solution,it is assumed that scale factor is a(t)~e^(Ht) as we considered previously for Bianchi type-I spacetime andΛ~a^(-2) as considered by Chen and Wu,where H is the Hubble constant and effective potential V(φ)=const;φHigg's field.It is shown that such a time varyingΛleads to no conflict with existing observations.However,it does change the predictions of standard cosmology in the matter-dominated phase and alleviates some problems in reconciling observations with the inflationary scenario.The model represents anisotropic spacetime in general.However,the model isotropizes for large values of t andβ=3H^(2),whereβis constant.The physical and geometrical aspects of the model in the context of an inflationary scenario is also discussed.

LRS Bianchi Type-II Cosmological Model with a Decaying Lambda Term

We consider a locally rotationally symmetric(LRS)Bianchi type-Ⅱspacetime with a perfect fluid and a variable cosmological constant∧.To solve the Einstein field equations we consider the cosmological term∧to be proportional to R^(-m) with R being the scale factor and m a constant[Phys.Rev.D 58(1998)043506].In this model we obtain∧~H^(2),∧~(R)/R and Larnbda~t^(-2),in agreement with the main dynamical laws for the decay of∧.The physical significance of the cosmological model is also discussed.

Locally Rotationally Symmetric Bianchi Type-II Magnetized String Cosmological Model with Bulk Viscous Fluid in General Relativity

The locally rotationally symmetric Bianchi type-II magnetized string cosmological model with bulk viscous fluid is investigated.The magnetic field is due to an electric current produced along the x−axis.Thus the magnetic field is in the y–z plane and F23 is the only non−vanishing component of electromagnetic field tensor Fij.To obtain the deterministic model in terms of cosmic time t,we have assumed the conditionξθ=const,whereξis the coefficient of bulk viscosity andθis the expansion in the model.

Reanalysis of energy band structure in the type-II quantum wells

Band structure analysis holds significant importance for understanding the optoelectronic characteristics of semiconductor structures and exploring their potential applications in practice. For quantum well structures, the energy of carriers in the well splits into discrete energy levels due to the confinement of barriers in the growth direction. However, the discrete energy levels obtained at a fixed wave vector cannot accurately reflect the actual energy band structure. In this work, the band structure of the type-II quantum wells is reanalyzed. When the wave vectors of the entire Brillouin region(corresponding to the growth direction) are taken into account, the quantized energy levels of the carriers in the well are replaced by subbands with certain energy distributions. This new understanding of the energy bands of low-dimensional structures not only helps us to have a deeper cognition of the structure, but also may overturn many viewpoints in traditional band theories and serve as supplementary to the band theory of low-dimensional systems.

腹腔镜结合Bianchi手术治疗腹股沟型隐睾的效果观察

目的:探讨腹腔镜下Bianchi手术方式治疗腹股沟型隐睾患儿的手术效果及安全性。方法:选取我院2019年6月至2022年6月收治的120例腹股沟区隐睾患儿作为研究对象,采用简单随机分组方式将其分为研究组和对照组各60例,研究组采用腹腔镜下Bianchi手术方式治疗,对照组采用腹股沟横向小切口睾丸下降术治疗,对比两组的手术操作指标、手术前后血清性激素、白细胞介素-6(IL-6)、IL-8、超敏C反应蛋白(hs-CRP)、血清抗苗勒管激素(AMH)、抑制素B(INHB)水平变化,手术并发症的发生情况。结果:研究组的平均手术时间长于对照组,住院时间短于对照组,术中出血量、切口长度均小于对照组,差异均具有统计学意义(P<0.05);术前,研究组和对照组的基线血清T、E2、FSH、AMH、INHB水平比较,差异不具有统计学意义(P>0.05);术后3个月再次对上述各项血清激素指标进行检查,两组患儿血清AMH、INHB水平较本组术前显著升高,血清E2、FSH水平较本组术前显著降低,差异均具有统计学意义(P<0.05);在两组患儿手术后3个月上述各项指标组间进行对比,差异均无统计学意义(P>0.05);术前,研究组和对照组的基线血清IL-6、IL-8、hs-CRP水平比较,差异不具有统计学意义(P>0.05);术后1d,研究组的血清IL-6、IL-8、hs-CRP测定值均低于对照组,差异均具有统计学意义(P<0.05);两组患儿手术后1d的IL-6、IL-8、hs-CRP测定值均高于本组术前,差异均具有统计学意义(P<0.05);研究组并发症发生率为8.33%,低于对照组的28.33%,差异具有统计学意义(P<0.05)。结论:腹腔镜下Bianchi手术方式治疗腹股沟型隐睾患儿的手术效果肯定,并发症少,值得临床推广应用。

单孔腹腔镜联合Bianchi手术治疗儿童高位隐睾的临床研究

目的探讨单孔腹腔镜联合Bianchi手术治疗儿童高位隐睾的临床疗效。方法回顾性分析2017年11月至2021年6月于牡丹江医学院附属红旗医院接受单孔腹腔镜联合Bianchi手术治疗的50例高位隐睾患儿(年龄6个月~7岁,平均年龄2.6岁)的临床资料,左侧隐睾18例,右侧隐睾27例,双侧隐睾5例;其中合并左侧腹股沟斜疝13例,右侧腹股沟斜疝18例,双侧腹股沟斜疝11例。所有患儿均行单孔腹腔镜联合Bianchi手术,观察患儿围手术期相关临床资料并对结果进行分析。结果50例患儿均成功完成手术,睾丸固定于阴囊内且无张力;术后随访1年,50例患儿均恢复良好,无睾丸萎缩、回缩、鞘膜积液及腹股沟斜疝等并发症,无明显手术瘢痕。结论单孔腹腔镜联合Bianchi手术治疗儿童高位隐睾具有安全、美观、并发症少等优点,是一种可行的微创技术。

Reliability Analysis of HEE Parameters via Progressive Type-II Censoring with Applications

A new extended exponential lifetime model called Harris extended-exponential(HEE)distribution for data modelling with increasing and decreasing hazard rate shapes has been considered.In the reliability context,researchers prefer to use censoring plans to collect data in order to achieve a compromise between total test time and/or test sample size.So,this study considers both maximum likelihood and Bayesian estimates of the Harris extended-exponential distribution parameters and some of its reliability indices using a progressive Type-II censoring strategy.Under the premise of independent gamma priors,the Bayesian estimation is created using the squared-error and general entropy loss functions.Due to the challenging form of the joint posterior distribution,to evaluate the Bayes estimates,samples from the full conditional distributions are generated using Markov Chain Monte Carlo techniques.For each unknown parameter,the highest posterior density credible intervals and asymptotic confidence intervals are also determined.Through a simulated study,the usefulness of the various suggested strategies is assessed.The optimal progressive censoring plans are also shown,and various optimality criteria are investigated.Two actual data sets,taken from engineering and veterinary medicine areas,are analyzed to show how the offered point and interval estimators can be used in practice and to verify that the proposed model furnishes a good fit than other lifetimemodels:alpha power exponential,generalized-exponential,Nadarajah-Haghighi,Weibull,Lomax,gamma and exponential distributions.Numerical evaluations revealed that in the presence of progressively Type-II censored data,the Bayes estimation method against the squared-error(symmetric)loss is advised for getting the point and interval estimates of the HEE distribution.

单孔腹腔镜辅助Bianchi手术治疗合并鞘状突未闭的滑动性隐睾

目的探讨单孔腹腔镜辅助Bianchi手术在合并鞘状突未闭的滑动性隐睾或低位隐睾手术中的应用价值。方法取患侧阴囊部横行切口,逐层进入,打开鞘膜囊,暴露睾丸(了解睾丸大小、精索血管及输精管的发育情况),横断鞘状突分离至高位后丝线双重结扎。结果手术时间20~45 min,平均39.9 min。出血少,1~2 ml。术后患儿疼痛症状轻,阴囊轻微肿胀,无须使用抗生素。术后6 h后开始流质饮食,术后2~3 d出院,无切口感染。33例术后随访0.5~6个月,平均4.8月,睾丸均停留在满意位置,外观良好,左右阴囊对称,无睾丸萎缩、睾丸回缩、鞘膜积液、腹股沟斜疝等并发症。结论单孔腹腔镜辅助Bianchi手术治疗合并鞘状突未闭的滑动性隐睾,更加容易达到下降固定睾丸及高位结扎疝囊的目的。

宇宙“常数”变化的Bianchi-Ⅰ型宇宙模型的解

在定域旋转对称的Bianchi-Ⅰ型时空中讨论了宇宙"常数"为变量的Einstein引力场方程的解.从能量动量守恒定律中包括真空的能量-动量T(vac)μν=-Λ(t)gμν的观点出发,得到了场方程的一个精确解,并对其相关的物理性质作了简要的讨论.这是一个较为普遍的解,它把文献中的结果作为特例包括在内.

Rational Engineering of Secondary Metabolic Pathways in a Heterologous Host to Enable the Biosynthesis of Hibarimicin Derivatives with Enhanced Anti-Melanomic Activity

A 61-kb biosynthetic gene cluster(BGC),which is accountable for the biosynthesis of hibarimicin(HBM)B from Microbispora rosea subsp.hibaria TP-A0121,was heterologously expressed in Streptomyces coelicolor M1154,which generated a trace of the target products but accumulated a large amount of shunt products.Based on rational analysis of the relevant secondary metabolism,directed engineering of the biosynthetic pathways resulted in the high production of HBM B,as well as new HBM derivates with improved antitumor activity.These results not only establish a biosynthetic system to effectively synthesize HBMs-a class of the largest and most complex Type-Ⅱpolyketides,with a unique pseudo-dimeric structure-but also set the stage for further engineering and deep investigation of this complex biosynthetic pathway toward potent anticancer drugs.

Computational Analysis of Novel Extended Lindley Progressively Censored Data

A novel extended Lindley lifetime model that exhibits unimodal or decreasing density shapes as well as increasing,bathtub or unimodal-then-bathtub failure rates, named the Marshall-Olkin-Lindley (MOL) model is studied.In this research, using a progressive Type-II censored, various inferences of the MOL model parameters oflife are introduced. Utilizing the maximum likelihood method as a classical approach, the estimators of themodel parameters and various reliability measures are investigated. Against both symmetric and asymmetric lossfunctions, the Bayesian estimates are obtained using the Markov Chain Monte Carlo (MCMC) technique with theassumption of independent gamma priors. From the Fisher information data and the simulatedMarkovian chains,the approximate asymptotic interval and the highest posterior density interval, respectively, of each unknownparameter are calculated. Via an extensive simulated study, the usefulness of the various suggested strategies isassessedwith respect to some evaluationmetrics such as mean squared errors, mean relative absolute biases, averageconfidence lengths, and coverage percentages. Comparing the Bayesian estimations based on the asymmetric lossfunction to the traditional technique or the symmetric loss function-based Bayesian estimations, the analysisdemonstrates that asymmetric loss function-based Bayesian estimations are preferred. Finally, two data sets,representing vinyl chloride and repairable mechanical equipment items, have been investigated to support theapproaches proposed and show the superiority of the proposed model compared to the other fourteen lifetimemodels.

From Control Theory to Gravitational Waves

When D:ξ→η is a linear ordinary differential (OD) or partial differential (PD) operator, a “direct problem” is to find the generating compatibility conditions (CC) in the form of an operator D1:η→ξ such that Dξ = η implies D1η = 0. When D is involutive, the procedure provides successive first-order involutive operators D1,...,Dn when the ground manifold has dimension n. Conversely, when D1 is given, a much more difficult “inverse problem” is to look for an operator D:ξ→η having the generating CC D1η = 0. If this is possible, that is when the differential module defined by D1 is “torsion-free”, that is when there does not exist any observable quantity which is a sum of derivatives of η that could be a solution of an autonomous OD or PD equation for itself, one shall say that the operator D1 is parametrized by D. The parametrization is said to be “minimum” if the differential module defined by D does not contain a free differential submodule. The systematic use of the adjoint of a differential operator provides a constructive test with five steps using double differential duality. We prove and illustrate through many explicit examples the fact that a control system is controllable if and only if it can be parametrized. Accordingly, the controllability of any OD or PD control system is a “built in” property not depending on the choice of the input and output variables among the system variables. In the OD case and when D1 is formally surjective, controllability just amounts to the formal injectivity of ad(D1), even in the variable coefficients case, a result still not acknowledged by the control community. Among other applications, the parametrization of the Cauchy stress operator in arbitrary dimension n has attracted many famous scientists (G. B. Airy in 1863 for n = 2, J. C. Maxwell in 1870, E. Beltrami in 1892 for n = 3, and A. Einstein in 1915 for n = 4). We prove that all these works are already explicitly using the self-adjoint Einstein operator, which cannot be parametrized and the comparison needs no comment. As a byproduct, they are all based on a confusion between the so-called div operator D2 induced from the Bianchi operator and the Cauchy operator, adjoint of the Killing operator D which is parametrizing the Riemann operator D1 for an arbitrary n. This purely mathematical result deeply questions the origin and existence of gravitational waves, both with the mathematical foundations of general relativity. As a matter of fact, this new framework provides a totally open domain of applications for computer algebra as the quoted test can be studied by means of Pommaret bases and related recent packages.

Bianchi型宇宙的量子化

本文将Ｗｈｅｅｌｅｒ—ＤｅＷｉｔｔ方程的平方根形式用于具有辐射场源的Ｂｉａｎｃｈｉ—Ⅰ型宇宙组成的微超空间模型，由此导出一个具有守恒流和正定几率密度的宇宙波函数．本文探讨了Ｂｉａｎｃｈｉ型宇宙的３次量子化，把类似于弯曲时空中量子场论程序应用到各向异性的Ｂｉａｎｃｈｉ—Ⅲ型宇宙中，给出了Ｗｈｅｅｌｅｒ—ＤｅＷｉｔｔ方程所满足的宇宙波函数解．把波函数作为微超空间中宇宙场算符看待后，不仅能解决量子宇宙学中几率解释的困难，而且也能得到宇宙多次产生的结论．同时估算了各种宇宙从“无”产生平均数目，给出了宇宙生成的分布，发现它遵从Ｐｌａｎｃｋ分布．

Bianchi恒等式的证明与应用

利用协变微分及反对称性证明了Bianchi恒等式,并加以应用.改进了部分学者的证明方法,为初学者提供了通俗易懂的证明思路与应用技巧.

Interacting viscous dark energy in a Bianchi type-Ⅲ universe

We study the evolution of the equation of state of viscous dark energy in the scope of Bianchi type III space-time. We consider a case where the dark energy is minimally coupled to the perfect fluid, as well as in direct interaction with it. The viscosity and the interaction between the two fluids are parameterized by constants 40 and σ, respectively. We have made a detailed investigation of the cosmological implications of this parametrization. To differentiate between different dark energy models, we have performed a geometrical diagnostic by using the statefinder pair {s, r}.

改良Bianchi术治疗中低位双侧隐睾的体会

目的：探讨改良Bianchi术治疗双侧中低位隐睾的可行性。方法：从2012年1月~2014年2月,采用改良Bianchi术治疗双侧中低位隐睾12例,其中,低位9例（包括滑动性隐睾2例）,中位3例。该组患儿年龄0.6~4.8岁,平均1.3岁。采取经阴囊中缝单一切口入路进行手术,术后所有患儿平均随访10个月。结果：12例患儿均成功完成手术,未出现并发症,平均手术时间低于传统术式,两者比较,差异有统计学意义,P〈0.01。结论：改良Bianchi术治疗双侧中低位隐睾具有损伤小,切口隐蔽,与传统手术方法相比在手术时间以及术后恢复方面优势明显,有一定推广应用价值。

腹腔镜下辅助Bianchi手术治疗鞘状突未闭的低位隐睾临床研究

隐睾是小儿泌尿科常见的疾病,有研究表明,隐睾的发生与不育及癌变有关,特别是腹腔内隐睾及双侧隐睾。经流行病学调查显示,隐睾在早产儿中占20%-30%[1]。按睾丸所处位置,隐睾分为高位隐睾和低位隐睾。高位隐睾约占20%[2]。临床上将在体检时能在腹股沟区触及睾丸者称为低位隐睾。据文献报道隐睾者约65%伴有鞘状突未闭[3],手术可采用传统经腹股沟切口的睾丸下降固定术,但术中由于过度游离精索及输精管,破坏腹股沟管正常结构,同时损失了部分睾丸血供,手术创伤大,手术操作复杂。

改良Bianchi睾丸下降固定术治疗中低位隐睾的临床疗效

目的:探讨改良Bianchi(阴囊中缝切口)睾丸下降固定术与传统(腹股沟联合阴囊切口)睾丸下降固定术的优缺点。方法:2013年2月至2014年2月收治的所有82例中低位隐睾患儿中,随机对其中46例(53侧睾丸)行改良Bianchi睾丸下降固定术作为观察组;传统方法即经腹股沟联合阴囊切口治疗36例(40侧)作为对照组。比较2组手术时间、术后并发症等方面的差异。结果:观察组与对照组患儿的手术时间分别为(25±6)min和(35±4)min,两组比较差异有统计学意义(P<0.01);经过1~2年的随访比较,均未出现睾丸萎缩情况;观察组患儿出现3例睾丸上缩情况,对照组出现2例术后睾丸上缩,发生率的差异没有统计学意义;术后均未出现腹股沟斜疝、鞘膜积液的并发症,但对照组患儿有1例出现腹股沟处切口血肿且所有患儿切口均较明显,而观察组术后手术切口几乎观察不到。结论:行改良Bianchi睾丸下降固定术治疗中低位隐睾效果满意,较传统手术在手术时间和切口美观等方面具有一定的优势,值得临床推广。

腹腔镜结合Bianchi手术治疗低位隐睾

目的探讨腹腔镜结合Bianchi手术治疗低位隐睾的应用价值。方法2018年6月~2020年12月,对22例小儿低位隐睾采用腹腔镜结合Bianchi手术治疗。腹腔镜探查如存在鞘状突未闭,先行高位结扎。结果22例手术均获成功,13例单侧隐睾中7例患侧鞘状突未闭,2例对侧鞘状突未闭;9例双侧隐睾中5例双侧鞘状突未闭,1例单侧鞘状突未闭。单侧隐睾手术时间20~30 min,双侧隐睾手术时间35~40 min,术中出血均<5 ml。随访1~12个月,平均6个月,超声提示双侧睾丸位于阴囊内,无鞘膜积液、精索血肿、睾丸萎缩等并发症。结论腹腔镜结合Bianchi手术治疗低位隐睾,既保留Bianchi手术的优点,又容易达到下降睾丸至阴囊底及高位结扎鞘状突的目的。