对于WEEE和RoHS,我们是不是找错了重点?

对于是否能找到达标的部件来满足WEEE和RoHS指令的要求,我们早已经被灌输得很多了,以至于我们忽视了一个更加重要的问题。这些指令的最终目的并不是要确保产品达标,或者开发出有效的回收计划,而是要避免使用有害物质,进而也就不需要回收计划了。     

Intracranial Pressure Telemetry System Using Semicustom Integrated Circuits

A new generation of implantable, telemetric transmitters for intracranial pressure (ICP) measurements have been developed. A unique technique used in packaging the silicon piezoresistive pt essure transducer provides excellent long-term stability. Pulse code modulation is used for data transmission over a radio frequency (RF) link. To minimize the component count, two semicustom, bipolar integrated circuits are used. The transmitter electronics are housed inside a 29 ×20 ×7 mm titanium package along with the pressure transducer and two lithium batteries. Even though the transmitter consumes less than 0.4 mW of power, it is turned on remotely via RF signal transduction only on demand in order to extend the lifetime of the batteries to years. The pressure input of the transmitter has a dynamic range of ?100- +200 mmHg with a 0.3 mmHg resolution and a 1 mmHg accuracy. Long-term in vitro and in vivo pressure baseline stabilities of better than 1 and 2 mmHg per month, respectively, have been achieved.     

Adventitial Tertiary Lymphoid Organs as Potential Source of MicroRNA Biomarkers for Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) is an inflammatory disease associated with marked changes in the cellular composition of the aortic wall. This study aims to identify microRNA (miRNA) expression in aneurysmal inflammatory cells isolated by laser microdissection from human tissue samples. The distribution of inflammatory cells (neutrophils, B and T lymphocytes, mast cells) was evaluated in human AAA biopsies. We observed in half of the samples that adventitial tertiary lymphoid organs (ATLOs) with a thickness from 0.5 to 2 mm were located exclusively in the adventitia. Out of the 850 miRNA that were screened by microarray in isolated ATLOs (n = 2), 164 miRNAs were detected in ATLOs. The three miRNAs (miR-15a-3p, miR-30a-5p and miR-489-3p) with the highest expression levels were chosen and their expression quantified by RT-PCR in isolated ATLOs (n = 4), M1 (n = 2) and M2 macrophages (n = 2) and entire aneurysmal biopsies (n = 3). Except for the miR-30a-5p, a similar modulation was found in ATLOs and the two subtypes of macrophages. The modulated miRNAs were then evaluated in the plasma of AAA patients for their potential as AAA biomarkers. Our data emphasize the potential of miR-15a-3p and miR-30a-5p as biomarkers of AAA but also as triggers of ATLO evolution. Further investigations will be required to evaluate their targets in order to better understand AAA pathophysiology.     

Risk-based approach to evaluate the public health benefit of additional wastewater treatment

The City of Stockton, CA operates a wastewater treatment facility that discharges tertiary treated effluent during the summer and secondary treated effluent during the winter to the San Joaquin River. Investigations were carried out between 1996 and 2002 to provide insight regarding the potential public health benefit that may be provided by year-round tertiary treatment. A hydraulic model of the San Joaquin River and a dynamic disease transmission model integrated a wide array of disparate data to estimate the level of viral gastroenteritis in the population under the two treatment scenarios. The results of the investigation suggest that risk of viral gastroenteritis attributable to the treatment facility under the existing treatment scheme is several orders of magnitude below the 8-14 illnesses per 1000 recreation events considered tolerable by U.S. EPA, and winter tertiary treatment would further reduce the existing risk by approximately 15-50%. The methodologies employed herein are applicable to other watersheds where additional water treatment is being considered to address public health concerns from recreation in receiving waters.     

Phase equilibria in the Nb-Ge-C system

An experimental survey of the Nb-Ge-C ternary phase diagram was used to determine the equilibrium tie-lines between solid phases in this system. In addition to the binary phases, the system contains a newly discovered ternary phase with an approximate composition of Nb₃GeC, and an extensive solution phase extending into the ternary system from the binary β-Nb₅Ge₃ phase.     

Prenatal cocaine exposure induces deficits in Pavlovian conditioning and sensory preconditioning among infant rat pups.

Offspring derived from Sprague-Dawley dams that received daily sc injection of 40 mg/kg 3 cc–2 cocaine hydrochloride (C40) or saline (LC) from Gestational Days 8–20 were tested for first-order Pavlovian conditioning and sensory preconditioning at Postnatal Days 8 (P8), P12, and P21. Although C40 dams gained significantly less weight than LC dams, pup body weights did not differ between the 2 groups. Significant sensory preconditioning was obtained at P8 and P12 (but not at P21) in LC offspring, confirming previous reports (e.g., L. P. Spear et al; see record 1989-35900-001) of decline in performance in this task during ontogeny. In contrast, C40 offspring failed to exhibit sensory preconditioning at any test age. In addition, C40 pups tested at P8 did not display significant first-order conditioning. Taken together these results suggest a more general deficit in cognitive functioning rather than a delay in cognitive development in prenatally cocaine-exposed offspring. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experimental Evidence for the Existence of the Ti3B4 Phase

Experimental evidence for the formation of Ti₃B₄ with an orthorhombic Ta₃B₄-type structure is presented. This phase forms by a peritectic reaction between TiB₂ and liquid at ∼2200°C and is stable to temperatures at least as low as 1690°C, the lowest temperature at which samples were annealed. No evidence was found to indicate the presence of a second high-temperature form of this phase, as has been reported in the literature.     

Agreement and clinical utility of 2 techniques for measuring cardiac output in patients with low cardiac output

BACKGROUND: The reliability of cardiac output obtained with the bolus technique is a problem. OBJECTIVES: To compare measurements of cardiac output measured with bolus and continuous techniques in patients with low cardiac output and to determine if measurements obtained with the continuous technique increased the number of subsequent clinical decisions. METHODS: In 60 intensive care patients, a nurse recorded a single continuous cardiac output measurement and then obtained the mean of 3 consecutive bolus determinations. The medical records of these 60 patients (experimental group) for the next 48 hours and of 60 other patients with regular or mixed venous oximetry catheters (control group) were reviewed to assess the occurrence of cardiac output events and the frequency of clinical decisions based on the events. RESULTS: Mean cardiac output was 4.46 L/min by the continuous technique and 5.20 L/min by the bolus technique (P = .011) for the experimental group. Median bias between the 2 types of measurements was -0.10 L/min (P = .79). Twenty-three of the pairs (38%) had an absolute percent difference greater than 15%. Of these, 18 (78%) had a higher bolus reading. Treatment decisions per 48 hours were 9.9 for the experimental group and 8.6 for the control group (P = .014). Median length of stay was 2 days less in the experimental group (P = .02), and mean highest cardiac output was 0.81 L/min higher (P = .009). CONCLUSIONS: Measurements of cardiac output determined with the continuous technique may be more precise than measurements determined with the bolus technique. Continuous cardiac output information increases the number of treatment decisions and actions that may shorten hospital length of stay.     

Percutaneous catheter drainage of tension pneumatocele, secondarily infected pneumatocele, and lung abscess in children

OBJECTIVE: To describe the use of percutaneous catheter drainage of tension pneumatocele, secondarily infected pneumatocele, and lung abscess in children. DESIGN: Retrospective case series. SETTING: A 24-bed pediatric intensive care unit. PATIENTS: Patients with tension pneumatocele, secondarily infected pneumatocele, or lung abscess. Tension pneumatocele was defined as an expanding intraparenchymal cyst compressing adjacent areas of the lung. Infected pneumatocele and lung abscess were defined, respectively, as intraparenchymal thin-walled cyst or thick-walled cavity containing an air-fluid level and purulent fluid. INTERVENTIONS: Seven pneumatoceles/lung abscesses were percutaneously drained in five patients. After computed tomography of the chest was obtained to localize the optimum site for drainage, a modified Seldinger technique was used to insert an 8.5-Fr soft catheter percutaneously into the cyst/cavity. The catheter was left in place until drainage (fluid and air) stopped. MEASUREMENTS AND MAIN RESULTS: All patients had clinical and radiologic improvement and were afebrile within 24 hrs after drainage. Bacterial culture grew aerobic bacteria from three cysts/cavities, anaerobic bacteria from one, and mixed bacteria from three. One patient had three secondarily infected pneumatoceles. Four of five secondarily infected pneumatoceles were under tension in two patients receiving mechanical ventilation. In both patients, the trachea was extubated within 24 hrs of drainage after prolonged mechanical ventilation. The number of days the catheter was in place ranged from 1 to 20 days. CONCLUSIONS: Percutaneous catheter drainage of tension pneumatocele, secondarily infected pneumatocele, and lung abscess can be performed safely and effectively in children. Early drainage is helpful, both as a diagnostic and therapeutic procedure. Drainage of tension pneumatocele may assist in weaning from mechanical ventilation. Computed tomography of the chest is helpful in determining the optimum site for percutaneous drainage.     

Amorphous-silicon field-effect device and possible application

The characteristics of an insulated-gate field-effect transistor made from amorphous silicon (a-Si) deposited in a glow discharge are discussed. It is suggested that the a-Si device could be applied with advantage in an addressable matrix of a liquid-crystal display panel.