Reusable Polyacrylonitrile-Sulfur Extractor of Heavy Metal Ions from Wastewater

Mercury, lead, and cadmium are among the most toxic and carcinogenic heavy metal ions (HMIs), posing serious threats to the sustainability of aquatic ecosystems and public health. There is an urgent need to remove these ions from water by a cheap but green process. Traditional methods have insufficient removal efficiency and reusability. Structurally robust, large surface-area adsorbents functionalized with high-selectivity affinity to HMIs are attractive filter materials. Here, an adsorbent prepared by vulcanization of polyacrylonitrile (PAN), a nitrogen-rich polymer, is reported, giving rise to PAN-S nanoparticles with cyclic π-conjugated backbone and electronic conductivity. PAN-S can be coated on ultra-robust melamine (ML) foam by simple dipping and drying. In agreement with hard/soft acid/base theory, N- and S-containing soft Lewis bases have strong binding to Hg²⁺, Pb²⁺, Cu²⁺, and Cd²⁺, with extraordinary capture efficiency and performance stability. Furthermore, the used filters, when collected and electrochemically biased in a recycling bath, can release the HMIs into the bath and electrodeposit on the counter-electrode as metallic Hg⁰, Pb⁰, Cu⁰, and Cd⁰, and the PAN-S@ML filter can then be reused at least 6 times as new. The electronically conductive PAN-S@ML filter can be fabricated cheaply and holds promise for scale-up applications.     

安全信用评价在乌弄龙、里底水电工程建设中的应用

近年来澜沧江公司对安全生产工作采取了强有力手段,安全生产基础不断夯实。如何将安全工作推进更深的层次,如何把控"准入关",将信用评价纳入安全生产不失为一个行之有效的方式。安全信用评价是建立水电工程施工安全信用体系的重要手段,能够促进整体行业安全管理水平的提升。     

Reaction of cytochrome P450 with cumene hydroperoxide: ESR spin-trapping evidence for the homolytic scission of the peroxide O-O bond by ferric cytochrome P450 1A2

ESR spin trapping was used to investigate the reaction of rabbit cytochrome P450 (P450) 1A2 with cumene hydroperoxide. Cumene hydroperoxide-derived peroxyl, alkoxyl, and carbon-centered radicals were formed and trapped during the reaction. The relative contributions of each radical adduct to the composite ESR spectrum were influenced by the concentration of the spin trap. Computer simulation of the experimental data obtained at various 5,5-dimethyl-1-pyrroline N-oxide (DMPO) concentrations was used to quantitate the contributions of each radical adduct to the composite ESR spectrum. The alkoxyl radical was the initial radical produced during the reaction. Experiments with 2-methyl-2-nitrosopropane identified the carbon-centered adducts as those of the methyl radical, hydroxymethyl radical, and a secondary carbon-centered radical. The reaction did not require NADPH-cytochrome P450 reductase or NADPH. It is concluded that the reaction involves the initial homolytic scission of the peroxide O-O bond to produce the cumoxyl radical. Methyl radicals were produced from the beta-scission of the cumoxyl radical. The peroxyl adduct was not observed in the absence of molecular oxygen. We conclude that the DMPO peroxyl radical adduct detected in the presence of oxygen was due to the methylperoxyl radical formed by the reaction of the methyl radical with oxygen. At a higher P450 concentration, a protein-derived radical adduct was also detected.     

Prevention of violence

Primary care physicians can easily incorporate efforts toward the primary and secondary prevention of family violence into their practices. By designing a preventive effort using the phases of the family life cycle, a developmentally appropriate system of prevention is created. The anticipatory guidance at each (annual) visit acknowledges family transitions and assures the family that abuse is a health issue and that the physician is a resource for issues of violence prevention. Using the FLC, the first phase is Coupling, when there is a risk of partner violence that continues as long as there is a partnership. Pregnancy and childbirth bring concerns of child neglect and battery. Older children are at additional risk for child sexual abuse. As families age, risks develop for elder abuse, too. The regular discussion of these issues raises the awareness that the potential for family violence continues over the life span and allows the physician opportunities to assess the risk of violence in that family and make appropriate preventive referrals. Primary care physicians are optimally positioned to address violence and its prevention in the office: they know and care for family units over time. Physicians are respected and trusted advisors who can become effective in preventing violence.     

The TINA initiative [intelligent networks]

The telecommunications information networking architecture (TINA), which builds on the current advances in broadband communication and distributed computing technologies, specifying a software-based architecture for future information networks that are required to transport multimedia information and manage multimedia communication, is described. An important aspect of the architecture is that service segment functions are separated from delivery segment functions. Another key aspect is the elimination of the rigid division between network applications and operations applications that exists in current-day networks. In the TINA architecture, both kinds of applications execute on a common distributed processing platform that hides from applications the effects and complexities introduced by distribution. The architecture supports application interoperability enabling flexible construction of services, composed of service components distributed across network domains, allowing network operators and service providers to cooperatively meet the needs of the user     

水蒸汽喷射泵系统实用设计软件的开发

本文在Turboc环境下开发了多级蒸汽喷射泵系统的设计软件，该软件包括了压缩比优化分配、单级喷射泵结构尺寸设计和冷凝器的结构尺寸设计等内容，使设计人员能够根据具体的工艺条件，快速地完成多级喷射泵系统的设计，对于提高多级喷射泵系统的工作稳定性、节省能源具有实际意义。     

Women, nutrition and exercise: a review of athletes' intakes and a discussion of energy balance in active women

Given the heightened interest in nutritional aspects of exercise, and an increase in athletic participation by women, it appeared timely to review the nutritional implications of exercise in women. The initial part of this paper contains a compilation of published studies on the nutrient intakes of female athletes. These reveal that most groups of athletes have adequate nutrient intakes, and that their vitamin and mineral intakes appear to be superior to those of nonathletic women. The average energy intake of athletes in studies summarized in this paper was 2069 kcal, and for certain groups of athletes, energy intakes were even lower. How these women manage to train intensely while consuming energy intakes similar to those of sedentary women is not readily apparent, and for this reason, the remainder of the paper discusses energy balance as affected by activity. Methodological considerations related to assessment of the components of the energy balance equation (food intake, energy expenditure, and body energy stores) are presented, with a focus on considerations in women. The effects of activity on each of these components are then discussed in an attempt to determine whether some form of energy conservation may occur. Finally, effects of activity on the menstrual cycle are reviewed. The observed changes are discussed in relation to nutrition 1) in terms of how nutrition may play a role in their causation; and 2) in terms of their nutritional implications for the amenorrheic athlete, specifically as regards energy balance and bone density.