Randomized Row and Column Iterative Methods with a Quantum Computer

We consider the quantum implementations of the two classical iterative solvers for a system of linear equations, including the Kaczmarz method which uses a row of coefficient matrix in each iteration step, and the coordinate descent method which utilizes a column instead. These two methods are widely applied in big data science due to their very simple iteration schemes. In this paper we use the block-encoding technique and propose fast quantum implementations for these two approaches, under the assumption that the quantum states of each row or each column can be efficiently prepared. The quantum algorithms achieve exponential speed up at the problem size over the classical versions, meanwhile their complexity is nearly linear at the number of steps

Poly[[aqua­tris­(μ3-hexa­methyl­ene­tetra­mine-κ3 N,N′,N′′)tris­(p-toluene­sulfonato-κO)tris­ilver(I)] trihydrate]

There are three AgI cations, three p-toluene­sulfonate (pts) anions, three hexa­methyl­ene­tetra­mine (hmt) mol­ecules and four water mol­ecules in the asymmetric unit of the title coordination polymer, {[Ag3(C7H7O3S)3(C6H12N4)3(H2O)]·3H2O}n. Two of the pts anions show positional disorder of their O atoms in 0.60:0.40 and 0.50:0.50 ratios. The AgI ion is coordinated by three hmt mol­ecules in an approximate trigonal–planar AgN3 arrangement. In each case, longer Ag—O bonds to a water mol­ecule and a pts anion complete a distorted trigonal–bipyramidal AgN3O2 geometry for the metal ion. In the crystal, the bridging hmt mol­ecules and pts ions generate a wave-like layer parallel to (001) and O—H⋯O hydrogen-bonding inter­actions consolidate the packing

Quantum Circulant Preconditioner for Linear System of Equations

We consider the quantum linear solver for $Ax=b$ with the circulant preconditioner $C$. The main technique is the singular value estimation (SVE) introduced in [I. Kerenidis and A. Prakash, Quantum recommendation system, in ITCS 2017]. However, some modifications of SVE should be made to solve the preconditioned linear system $C^{-1} Ax = C^{-1} b$. Moreover, different from the preconditioned linear system considered in [B. D. Clader, B. C. Jacobs, C. R. Sprouse, Preconditioned quantum linear system algorithm, Phys. Rev. Lett., 2013], the circulant preconditioner is easy to construct and can be directly applied to general dense non-Hermitian cases. The time complexity depends on the condition numbers of $C$ and $C^{-1} A$, as well as the Frobenius norm $\|A\|_F$

Amide Activation by Tf2O: Reduction of Amides to Amines by NaBH4 under Mild Conditions

An expeditious and practical method for the reduction of amides to amines is reported. The method is consisted of activation of amides with Tf2O followed by reduction with sodium borohydride in THF at room temperature. Various amides/lactams gave the corresponding amines in good to excellent yields, even with hindered amides and secondary amides. This method also presents other advantages such as TBDPS-group tolerance, short reaction time, simple workup and purification procedure.NSF of China [20832005]; National Basic Research Program (973 Program) of China [2010CB833200

A chalcone derivative reactivates latent HIV-1 transcription through activating P-TEFb and promoting Tat-SEC interaction on viral promoter.

The principal barrier to the eradication of HIV/AIDS is the existence of latent viral reservoirs. One strategy to overcome this barrier is to use latency-reversing agents (LRAs) to reactivate the latent proviruses, which can then be eliminated by effective anti-retroviral therapy. Although a number of LRAs have been found to reactivate latent HIV, they have not been used clinically due to high toxicity and poor efficacy. In this study, we report the identification of a chalcone analogue called Amt-87 that can significantly reactivate the transcription of latent HIV provirses and act synergistically with known LRAs such as prostratin and JQ1 to reverse latency. Amt-87 works by activating the human transcriptional elongation factor P-TEFb, a CDK9-cyclin T1 heterodimer that is part of the super elongation complex (SEC) used by the viral encoded Tat protein to activate HIV transcription. Amt-87 does so by promoting the phosphorylation of CDK9 at the T-loop, liberating P-TEFb from the inactive 7SK snRNP, and inducing the formation of the Tat-SEC complex at the viral promoter. Together, our data reveal chalcones as a promising category of compounds that should be further explored to identify effective LRAs for targeted reversal of HIV latency

Construction and characterization of a cDNA library from human brain glioma cell line U251 with overexpressed exogenous p53 gene

The tumor-suppressor gene p53 and its downstream genes consist of a complicated gene network, and the challenge to understand the network is to identify p53 downstream genes. In order to isolate and identify new p53 regulated genes, we constructed and characterized a normalized cDNA library from human brain glioma cell line U251 while exogenous p53 gene is overexpressed. The constructed cDNA library contained 1.3×106 directional recombinants, and its insert size ranged from 0.5 to 2.0 kb. Screening the cDNA library, we obtained two novel p53 downstream genes, PAP1 and PAP2. Polymerase chain reaction (PCR) analyses of the library for specific genes revealed the presence of cDNAs for p53 downstream genes such as p21, gadd45, and PCNA. These results demonstrate the sequence complexity and relatively low redundancy of our cDNA library. It is a valuable and unique resource for studying p53 gene expression, regulatory mechanisms and screening p53 downstream genes. Keywords: p53 Gene, p53 downstream gene, cDNA library, normalizationAfrican Journal of Biotechnology Vol. 9(33), pp. 5262-5268, 16 August, 201

Effect of Alisma plantago-aquatica Linn extract on hyperprolactinemia in rats

Purpose: To investigate the anti-hyperprolactinemia effect and mechanism of action of of Alisma plantago-aquatica Linn. extract (APLE) in rats. Methods: The hyperprolactinemia (hyperPRL) model of rats was established by intraperitoneal (i.p.) metoclopramide (200 mg/kg daily) for 10 days. Sixty rats were divided into six groups (n = 10 each): normal group), hyperPRL control group, hyperPRL plus 0.6 mg/kg bromocriptine (as a positive control) group, and hyperPRL plus high (14.4 g/kg), medium (7.2 g/kg), or low (3.6 g/kg) dose of APLE. Bromocriptine or vehicle control was administered to the rats daily for 30 days, and the hypothalamus dopamine D2 receptor, protein kinase A (PKA), and cyclic adenosine monophosphate (cAMP) levels were investigated by Western blot. Results: Compared with the normal rats, hypothalamus dopamine D2 receptor protein expression was significantly lower in hyperPRL rats (p < 0.01), but was changed significantly after 30-day doses (various) of APLE administration (3.6 g/kg, p < 0.05; 7.2 and 14.4 g/kg, p < 0.01). Compared with the control rats, hypothalamus PKA and cAMP levels were significantly higher in hyperPRL rats (p < 0.01). These increases in PKA and cAMP were significantly attenuated by 30-day of bromocriptine treatment or various doses of APLE (p < 0.01). Conclusion: The anti-hyperPRL activity of APLE is confirmed from the findings of this study Thus, the plant can potentially be developed into a new anti-hyperprolactinemia drug