Rational design of Rhizopus oryzae lipase with modified stereoselectivity toward triradylglycerols

The binding site of sn-1(3)-regioselective Rhizopus oryzae lipase (ROL) has been engineered to change the stereoselectivity of hydrolysis of triacylglycerol substrates and analogs. Two types of prochiral triradylglycerols were considered: 'flexible' substrates with ether, benzylether or ester groups, and 'rigid' substrates with amide or phenyl groups, respectively, in the sn-2 position. The molecular basis of sn-1(3) stereoselectivity of ROL was investigated by modeling the interactions between substrates and ROL, and the model was confirmed by experimental determination of the stereoselectivity of wild-type and mutated ROL. For the substrates, the following rules were derived: (i) stereopreference of ROL toward triradylglycerols depends on the substrate structure. Substrates with 'flexible' sn-2 substituents are preferably hydrolyzed at sn-1, 'rigid' substrates at sn-3. (ii) Stereopreference of ROL toward triradylglycerols can be predicted by analyzing the geometry of the substrate docked to ROL: if the torsion angle phiO3-C3 of glycerol is more than 150 degrees, the substrate will preferably be hydrolyzed in sn-1, otherwise in sn-3. For ROL, the following rules were derived: (i) residue 258 affects stereoselectivity by steric interactions with the sn-2 substituent rather than polar interactions. To a lower extent, stereoselectivity is influenced by mutations further apart (L254) from residue 258. (ii) With 'rigid' substrates, increasing the size of the binding site (mutations L258A and L258S) shifts stereoselectivity of hydrolysis toward sn-1, decreasing its size (L258F and L258F/L254F) toward sn-3.      

Reimagining future energy systems: Overview of the US program to maximize energy utilization via integrated nuclear-renewable energy systems

A sustainable, balanced energy portfolio is necessary for a country's continued economic growth. This portfolio must collectively be able to provide reliable, resilient electricity at stable, affordable prices. Nuclear energy is an important contributor to global clean energy supply, both as a primary source and by complementing and enabling other clean energy sources. As we look to the design and operation of future energy systems, we see an increasing need to think differently about how we utilize our energy resources to meet all of our energy needs—not just electricity but also industrial and transportation demands. Resource utilization in light of a broader desire to reduce environmental impacts leads us to consider transforming how we use nuclear energy, which currently provides more than half of the nonemitting electricity generated in the United States. A paradigm shift is required to develop optimal energy generation and use configurations that embrace novel approaches to system integration and process design. The US Department of Energy (DOE) Office of Nuclear Energy (NE) program on Integrated Energy Systems (IES)—formerly the Nuclear-Renewable Hybrid Energy Systems (N-R HES) program—was established to evaluate potential options for the coordinated use of nuclear and renewable energy generators to meet energy demands across the electricity, industrial, and transportation sectors. These formerly independent sectors are becoming increasingly linked through technology advances in data acquisition, communications, demand response approaches, and control technologies. Advanced modeling and simulation tools can be employed to design systems that better coordinate across these sectors. Implementation of integrated multi-input, multi-output energy systems will allow for expanded use of nuclear energy beyond the grid in a manner that complements the increased build-out of variable renewable energy generation. These integrated systems would provide enhanced flexibility while also providing energy services and supporting the production of additional, nonelectric commodities (eg, potable water, hydrogen, and liquid fuels) via excess thermal and electrical energy from the nuclear system. Increased flexibility of traditionally baseload nuclear systems will support energy security, grid reliability, and grid resilience while maximizing the use of clean energy technologies. This paper provides an overview of current efforts in the United States that assess the potential to increase utilization of nuclear energy systems, in concert with renewable energy generation, via the IES program. Analysis tools and approaches and preliminary analysis results are summarized, and planned experimental activities to demonstrate integrated system performance are introduced.     

Expanding yeast knowledge online

The completion of the Saccharomyces cerevisiae genome sequencing project¹¹ and the continued development of improved technology for large-scale genome analysis have led to tremendous growth in the amount of new yeast genetics and molecular biology data. Efficient organization, presentation, and dissemination of this information are essential if researchers are to exploit this knowledge. In addition, the development of tools that provide efficient analysis of this information and link it with pertinent information from other systems is becoming increasingly important at a time when the complete genome sequences of other organisms are becoming available. The aim of this review is to familiarize biologists with the type of data resources currently available on the World Wide Web (WWW). © 1998 John Wiley & Sons, Ltd.     

台北盆地动态参数之最佳化分析与验证

为探讨台北盆地之地盘震动特性 ,十多年来进行了许多现地和室内土壤动态试验 ,研究了将室内土壤参数修订成为相当于现地条件之原理以及鉴定惟一参数之最佳化分析方法 ,并以实际地震案例之PGA验证本文分析结果之正确性。     

Measuring behavioral regulation in four societies.

The present study examined the psychometric properties of scores from a direct measure of behavioral regulation, the Head–Toes–Knees–Shoulders task (HTKS) with 3- to 6-year-old children in the United States, Taiwan, South Korea, and China. Specifically, we investigated (a) the nature and variability of HTKS scores, including relations to teacher-rated classroom behavioral regulation; and (b) relations between the HTKS and early mathematics, vocabulary, and literacy skills. Higher HTKS scores were significantly related to higher teacher ratings of classroom behavioral regulation in the United States and South Korea but not in Taiwan and China. Also, higher HTKS scores were significantly related to higher early mathematics, vocabulary, and literacy skills beyond the influence of demographic variables and teacher-rated classroom behavioral regulation. These initial findings suggest that HTKS scores may be interpreted as reflecting early behavioral regulation in these 4 societies and that behavioral regulation is important for early academic success in the United States and in Asian countries. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A multicomponent intervention to prevent partner violence within an existing service intervention.

Intimate partner violence (IPV) is an enormous public health problem that results in injury, health problems, and substantial cost to society. Despite having a grasp of the scope of IPV, public health officials and workers know little about how to prevent it. The few empirically established primary prevention programs consist of school-based curricula targeting high school students. Additional venues for IPV prevention are needed, especially for women at elevated risk. This article describes a preventive intervention for IPV consisting of three components: (a) a structured assessment for IPV; (b) a brochure-driven intervention for women experiencing IPV, including safety planning, referrals, and advocacy; and (c) a skills-based curriculum delivered to all participants that focuses on improving relationship decisions and outcomes. While this intervention could potentially be delivered in a multitude of clinical settings, this article focuses on its delivery within a home visitation program for young, disadvantaged new mothers, a population known to be at increased risk for IPV. If found to be effective, this intervention could be incorporated into many service delivery systems, with broad-based clinical implications for IPV prevention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thrower's fracture: a comparison of two presentations of a rare fracture

We report two similar rare types of fracture of the lower end of the humerus sustained in fit young adults while throwing a ball. Both cases were seen within 1 week in a busy accident and emergency (A&E) department. The types of fracture in each case are unusual and, in the past, have been attributed to fatigue or to a repetitive strain pattern.