用于聚合物基微流体MEMS的等离子体活性晶圆键合技术

Lab-on-chip或μ-TAS(micro-totalanalysissystems)结合流体处理、检测及数据分析,是一种便携式的低成本高效器件。在微流体应用中,聚合物具有比硅或玻璃器件更明显的优势,它包括:宽泛的材料选择性,成本低、效率高,使用任意性,生物兼容性,抗化学品和工艺灵活性。为了实现采用这类材料制备小型集成化系统,我们发展了新的制备与封装技术。这项工作着眼于运用等离子体活化低温直接键合技术实现纳/微结构聚合物在低温条件下进行封装。由纳米压印光刻制作的纳/微结构的聚合物器件,可能是异质(聚合物与玻璃或硅)或同质(聚合物与聚合物)键合。为了改进键合材料的物理和化学熔合,键合工序通常在接近聚合物的玻璃化转变温度的高温下进行。但遗憾的是,高温损伤了微细图形,特别是对于高深宽比结构。在EVG810LT 等离子体反应室里,我们采用软射频频率等离子体表面处理,来进行聚合物的等离子体活化,它能在不改变聚合物体特性的前提下清洗和活化聚合物顶层。最终结果是,在EVG501晶圆键合机上,两个活化的表面在低温下通过施加一个适中的、均匀的接触压力而连接在一起,保证了空腔密封并防止了小结构的破坏和变形。键合工艺条件为:真空条件为从大气到200~1000Pa、接触压力为2～5kN、温度从室温到80℃。RR     

Jellyfish‐Based Smart Wound Dressing Devices Containing In Situ Synthesized Antibacterial Nanoparticles

Although the negative consequences of the global phenomenon of jellyfish (JF) swarms are well recognized, the use of their biomass for practical applications is mostly limited to a niche in the Asian food industry. This fact is quite surprising since JF's biomass comprises useful biomaterials such as Q‐mucin glycoprotein and collagen. In this work, the JF biomass, collected from two different species, is used to prepare electrospun scaffolds composed of nanometric “core–shell”‐type fibers, in which adjustment of the electrospinning process parameters can easily control their mechanical, morphological, and chemical properties. This nonwoven scaffold shows excellent biocompatibility and biodegradability, indicating suitability for biomedical research contexts. Performed cell proliferation assays show that the scaffold could support the growth of cardiac cells, fitting the requirement of tissue engineering. Additional incorporation of in situ‐generated silver nanoparticles in these nanofibers produced mats with potent antibacterial properties. Preclinical trials with the resulted mats on porcine wound healing models exhibit fast and complete healing of wounds.     

Formation and extraction of persistent fumigant residues in soils

Fumigants are commonly thought to be short-lived in soil, but residues have been found in soils years following application. In this study, formation and extraction of persistent soil fumigant residues were investigated. Fumigants 1,3-dichloropropene (1,3-D), chloropicrin (CP), and methyl isothiocyanate (MITC) were spiked into Arlington, Glenelg, and Hagerstown soils and incubated for 30 d under controlled conditions. The incubated soils were evaporated for 20 h prior to extraction with a variety of organic solvents at different temperatures. Extraction with acetonitrile in sealed vials at 80 degrees C for 24 h was the most efficient method to recover persistent soil fumigant residues. At application rates of 1000-1700 mg (kg of soil)(-1), persistent residues of 1,3-D, CP, and MITC in the three soils ranged from 5 to 67 mg kg(-1). The residue content increased with application rate, correlated positively with soil silt content, decreased dramatically as indigenous organic matter (OM) was removed, and changed little with external OM addition. Adsorption to clay surfaces was not important in fumigant retention, while pulverization of soil aggregates significantly decreased persistent fumigant residues. The results suggest that persistent fumigant residues are retained in soil intra-aggregate micropores resulting from binding clay flocs and silt particles by humic substances.     

Hygrothermal Properties of Adhesively Bonded Joints and Their Correlation with Bulk Adhesive Properties

The combined effects of heat (50[ddot]C) and humidity (95% R.H.) on the lap shear and T-peel strengths of 120[ddot]C, 150[ddot]C and 215[ddot]C service epoxy film adhesives have been characterized. Experimental results have indicated that effects of hygrothermal conditioning on lap shear and peel properties vary with exposure time and final testing temperatures and type of adhesive tested. In the cases where cohesive failure was observed in the shear and peel specimens, a correlation could be established between the bulk properties of the adhesives (tensile strength and elongation) and their adhesively bonded joint properties (shear and peel). When testing was carried out at room temperature, a general correlation between the tensile elongation and T-peel or shear could be obtained. At below freezing temperatures, lap shear strength seemed to be correlated with bulk tensile strength while peel correlated with bulk tensile elongation. At elevated temperatures, the relative contributions of bulk strength and elongation were the decisive factors as far as shear and peel strengths are concerned.     

Enhancing Photodynamic Therapy through Resonance Energy Transfer Constructed Near‐Infrared Photosensitized Nanoparticles

Photodynamic therapy (PDT) is an important cancer treatment modality due to its minimally invasive nature. However, the efficiency of existing PDT drug molecules in the deep‐tissue‐penetrable near‐infrared (NIR) region has been the major hurdle that has hindered further development and clinical usage of PDT. Thus, herein a strategy is presented to utilize a resonance energy transfer (RET) mechanism to construct a novel dyad photosensitizer which is able to dramatically boost NIR photon utility and enhance singlet oxygen generation. In this work, the energy donor moiety (distyryl‐BODIPY) is connected to a photosensitizer (i.e., diiodo‐distyryl‐BODIPY) to form a dyad molecule ( RET‐BDP ). The resulting RET‐BDP shows significantly enhanced absorption and singlet oxygen efficiency relative to that of the acceptor moiety of the photosensitizer alone in the NIR range. After being encapsulated with biodegradable copolymer pluronic F‐127‐folic acid (F‐127‐FA), RET‐BDP molecules can form uniform and small organic nanoparticles that are water soluble and tumor targetable. Used in conjunction with an exceptionally low‐power NIR LED light irradiation (10 mW cm^?2), these nanoparticles show superior tumor‐targeted therapeutic PDT effects against cancer cells both in vitro and in vivo relative to unmodified photosensitizers. This study offers a new method to expand the options for designing NIR‐absorbing photosensitizers for future clinical cancer treatments.     

Hypnosis for smoking cessation: a randomized trial

The purpose of this study was to determine whether hypnosis would be more effective in helping smokers quit than standard behavioral counseling when both interventions are combined with nicotine patches (NP). A total of 286 current smokers were enrolled in a randomized controlled smoking cessation trial at the San Francisco Veterans Affairs Medical Center. Participants in both treatment conditions were seen for two 60-min sessions, and received three follow-up phone calls and 2 months of NP. At 6 months, 29% of the hypnosis group reported 7-day point-prevalence abstinence compared with 23% of the behavioral counseling group (relative risk [RR] = 1.27; 95% confidence interval, CI 0.84-1.92). Based on biochemical or proxy confirmation, 26% of the participants in the hypnosis group were abstinent at 6 months compared with 18% of the behavioral group (RR = 1.44; 95% CI 0.91-2.30). At 12 months, the self-reported 7-day point-prevalence quit rate was 24% for the hypnosis group and 16% for the behavioral group (RR = 1.47; 95% CI 0.90-2.40). Based on biochemical or proxy confirmation, 20% of the participants in the hypnosis group were abstinent at 12 months compared with 14% of the behavioral group (RR = 1.40; 95% CI 0.81-2.42). Among participants with a history of depression, hypnosis yielded significantly higher validated point-prevalence quit rates at 6 and 12 months than standard treatment. It was concluded that hypnosis combined with NP compares favorably with standard behavioral counseling in generating long-term quit rates.     

Utility of citrate dialysate in management of acute kidney injury in children

Dialysis concentrate acidified with citrate as opposed to acetate has been reported to prevent clotting in hemodialysis circuits, and improve dialysis efficiency in adults. There is no information on its use in children. The purpose of the study was to evaluate the utility of citrate dialysate for renal replacement therapy in a pediatric population with acute kidney injury. We performed a retrospective review of our experience using Citrasate^® concentrate from December 2007 to August 2009. All treatments were provided using the Fresenius 2008 dialysis machine. Citrasate^® was utilized in 7 children aged 60.3±51.0 months (mean±SD), range 13 months to 12 years. The number of treatments varied from 4 to 31 (mean 12±8 treatments) for a total of 89 treatments. Rare sporadic mild hypocalcemia was noted but could not be definitively linked with the use of Citrasate^®. Four children also required low‐dose heparin (3.6–15 U/kg/h) due to clotting. Activated clotting times (when checked) were not affected by this low‐dose heparin therapy. Some degree of clotting occurred in 21 of 89 (23.5%) treatments. Early termination of treatment due to thrombosis was required in 7 of 89 (7.8%) treatments. In summary, use of Citrasate^® dialysis concentrate was well tolerated in critically ill children with acute kidney injury. Citrasate^® reduced but did not completely eliminate the need for heparin in our population. Further study in a more diverse population would be helpful.     

Therapy processes and outcomes of psychological interventions for women diagnosed with gynecological cancers: A test of the generic process model of psychotherapy.

Objective: Little attention has been paid to the role of nonspecific therapy processes in the efficacy of psychological interventions for individuals diagnosed with cancer. The goal of the current study was to examine the three constructs from the generic model of psychotherapy (GMP): therapeutic alliance, therapeutic realizations, and therapeutic openness/involvement in the treatment outcome of women with gynecological cancers attending either a 7-session supportive counseling intervention or a coping and communication skills intervention. Method: Two hundred and three women completed measures of alliance, realizations, and openness after Intervention Sessions 2, 3, and 6, as well as measures of depressive symptoms after these sessions and 6 months after the pre-intervention assessment (posttreatment). Results: Consistent with the GMP, in early sessions, therapeutic bond predicted openness in terms of positive affect experienced during sessions, and both aspects of openness (positive and negative affect), in turn, predicted more therapeutic realizations. Therapeutic realizations predicted perceptions of greater session progress, and greater therapeutic bond predicted more therapeutic realizations. When early session GMP variables were used to predict later GMP processes and outcomes and posttreatment outcomes, early therapeutic bond predicted later session therapeutic realizations directly and indirectly via emotional arousal, emotional arousal predicted session progress, session progress predicted lower postsession depressive symptoms, and depressive symptoms as rated after Session 6 predicted depressive symptoms 3 months posttreatment. However, a number of additional associations among GMP processes were found. Conclusions: Our results suggest that therapy processes played a role in predicting both short- and long-term treatment outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reading achievement across three language groups: Growth estimates for overall reading and reading subskills obtained with the Early Childhood Longitudinal Survey.

This study estimated normative reading trajectories for the population of English-proficient language minority students attending U.S. public elementary schools. Achievement of English-language learners (ELLs) was evaluated in terms of native English speakers' progress, and estimates were adjusted for the effects of socioeconomic status (SES). The ELL group was disaggregated into native Spanish speakers and native speakers of Asian languages. Multilevel latent variable growth modeling indicated that achievement trends of Asian-language ELLs are more similar to those of native English speakers than to those of Spanish ELL groups. Spanish ELLs had lower initial reading achievement than both Asian-language ELLs and native English speakers, and Asian students had higher initial achievement than did the native English speaking group. Additionally, Spanish ELLs had statistically significantly less growth over time than did Asian ELLs, with differences being most notable on reading evaluation–related tasks. Language-related differences in total reading were minimized when SES effects were specifically modeled, suggesting that SES may be the more significant factor explaining the lower achievement rates of English-proficient native Spanish speakers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)