Towards the World's Smallest Gravimetric Particulate Matter Sensor: A Miniaturized Virtual Impactor with a Folded Design.

The increasing air pollution across the globe has given rise to a global health crisis that is increasing at an alarming rate. Every year, millions of people lose their lives due to health risks caused by air pollutants. Hence, there is a pressing need for better solutions to accurately measure the amount of air pollution. This work is aimed at designing a highly compact, accurate, low-cost, self-resettable, and easy-to-use gravimetric-based particulate matter sensor solution for portable applications. Previous attempts have failed to realize true miniaturization, due to the size constraints of the virtual impactor needed-a mechanism that segregates the particulate matters based on their sizes. Our complete particulate matter sensor solution consists of three components (i) a piezoelectric resonating membrane, (ii) a virtual impactor, and (iii) a thermophoretic mechanism to reset the sensor. This paper presents a novel design of the virtual impactor, based on a folded configuration. This helps realize the entire system in a volume of 20 mm × 20 mm × 10 mm. We report here the design, working principles, fabrication, and experimental results of the virtual impactor.

Design of an Integrated Micro-Viscometer for Monitoring Engine Oil.

This paper proposes a novel integrated micro-viscometer for engine-oil monitoring. The final solution consists of a capacitive micromachined ultrasonic transducer (CMUT) and an application-specific integrated circuit (ASIC). The CMUT is used to generate and capture acoustic waves while immersed in engine oil. The low power transceiver ASIC is interfaced with the CMUT structure for actuation and reception. An integrated charge pump boosts the supply voltage from 3.3 to 22 V to generate the DC polarization voltage of the CMUT. The receiver has a power consumption of 72 µW with an input-referred noise current of 3.2pAHz and a bandwidth of 7 MHz. The CMUT array occupies an area of 3.5 × 1 mm, whereas the ASIC has a chip area of 1 × 1 mm. The system was tested using engine oils of different types and ages at different temperatures. Measurement results show a significant frequency shift due to the dynamic viscosity change that occurs as oil ages. A shift of -1.9 kHz/cP was measured, which corresponds to a shift of 33 Hz/mile. This work paves the way for high accuracy-integrated solutions for oil condition monitoring and is expected to play a significant role in a more economic and environmentally friendly usage of oil.

Dual-Level Capacitive Micromachined Uncooled Thermal Detector.

This paper presents a novel dual-level capacitive microcantilever-based thermal detector that is implemented in the commercial surface micromachined PolyMUMPs technology. The proposed design is implemented side-by-side with four different single-level designs to enable a design-to-design performance comparison. The dual-level design exhibits a rate of capacitance change per degree Celsius that is over three times higher than that of the single-level designs and has a base capacitance that is more than twice as large. These improvements are achieved because the dual-level architecture allows a 100% electrode-to-detector area, while single-level designs are shown to suffer from an inherent trade-off between sensitivity and base capacitance. In single-level designs, either the number of the bimorph beams or the capacitance electrode can be increased for a given sensor area. The former is needed for a longer effective length of the bimorph for higher thermomechanical sensitivity (i.e., larger tilting angels per degree Celsius), while the latter is desired to relax the read-out integrated-circuits requirements. This thermomechanical response-to-initial capacitance trade-off is mitigated by the dual-level design, which dedicates one structural layer to serve as the upper electrode of the detector, while the other layer contains as many bimorph beams as desired, independently of the former's area.

Morphological analysis of circulating tumour cells in patients undergoing surgery for non-small cell lung carcinoma using the isolation by size of epithelial tumour cell (ISET) method.

BACKGROUND AND OBJECTIVE: Recurrence rates after surgery for non-small cell lung cancer (NSCLC) range from 25 to 50% and 5-year survival is only 60-70%. Because no biomarkers are predictive of recurrence or the onset of metastasis, pathological TNM (pTNM) staging is currently the best prognostic factor. Consequently, the preoperative detection of circulating tumour cells (CTCs) might be useful in tailoring therapy. The aim of this study was to characterize morphologically any circulating non-haematological cells (CNHCs) in patients undergoing surgery for NSCLC using the isolation by size of epithelial tumour cell (ISET) method. METHODS: Of 299 blood samples tested, 250 were from patients with resectable NSCLC and 59 from healthy controls. The presence of CNHCs was assessed blindly and independently by 10 cytopathologists on May-Grünwald-Giemsa stained filters and the cells classified into three groups: (i) malignant cells, (ii) uncertain malignant cells, and (iii) benign cells. We assessed interobserver agreement using Kappa (κ) analysis as the measure of agreement. RESULTS: A total of 123 out of 250 (49%) patients showed CNHCs corresponding to malignant, uncertain malignant and benign cells, in 102/250 (41%), 15/250 (6%) and 6/250 (2%) cases, respectively. No CNHCs were detected in the blood of healthy subjects. Interobserver diagnostic variability was absent for CNHCs, low for malignant cells and limited for uncertain malignant and benign cells. CONCLUSION: Identification of CTCs in resectable NSCLC patients, using ISET technology and according to cytopathological criteria of malignancy, appears to be a new and promising field of cytopathology with potential relevance to lung oncology.

Hard-Baked Photoresist as a Sacrificial Layer for Sub-180 °C Surface Micromachining Processes.

This letter proposes a method for utilizing a positive photoresist, Shipley 1805, as a sacrificial layer for sub-180 °C fabrication process flows. In the proposed process, the sacrificial layer is etched at the end to release the structures using a relatively fast wet-etching technique employing resist remover and a critical point dryer (CPD). This technique allows high etching selectivity over a large number of materials, including silicon-based structural materials such as silicon-carbide, metals such as titanium and aluminum, and cured polymers. This selectivity, as well as the low processing thermal budget, introduces more flexibility in material selection for monolithic integration above complementary metal oxide semiconductor (CMOS) as well as flexible substrates.

Cyclosporine lymphocyte maximum level monitoring in de novo kidney transplant patients: a prospective study.

OBJECTIVES: To determine prospectively the temporal variations of cyclosporine-A lymphocyte maximum level, whole blood maximum concentration, and total lymphocyte count in patients with de novo kidney transplantation. MATERIALS AND METHODS: Lymphocyte maximum level, whole blood maximum concentration, and total lymphocyte count were prospectively measured in 35 patients at 1, 2, and 3 months after kidney transplantation. Two groups--a biopsy-proven acute rejection group (REJ+) and a rejection-free group (REJ-)--were compared. RESULTS: Both groups had similar lymphocyte maximum levels, whole blood maximum concentrations, and total lymphocyte counts at the first month after transplantation. REJ+ patients had significantly lower lymphocyte maximum levels at 2 and 3 months (59+/-34 and 33+/-9 pg/Lc) and higher total lymphocyte counts (0.00204+/-0.00078x10(9)/L and 0.00203+/-0.00022x10(9)/L) when compared with their REJ- counterparts (87+/-56 and 63+/-30 pg/Lc, P<.05 and P<.007) and (0.00137+/-0.00074x10(9)/L and 0.0015+/-0.0006x10(9)/L, P<.02 and P<.003) respectively. Whole blood maximum concentrations were significantly higher in patients in the REJ+ group (2050+/-623 vs 1414+/-536 ng/mL, P<.02) at 2 months. At 3 months, the 2 groups were comparable (1158+/-340 vs 1365+/-525 ng/mL, P=NS). CONCLUSIONS: These results suggest that acute rejection is associated with a relatively low cyclosporine- A lymphocyte maximum level and high total lymphocyte count in the early posttransplant period. Cyclosporine-A whole blood maximum concentration failed to correlate with clinical outcome. Cyclosporine-A lymphocyte maximum level seems to offer a more reliable alternative than does whole blood maximum concentration for cyclosporine-A monitoring in patients with kidney transplantation.

Mycophenolic acid plasma trough level: correlation with clinical outcome.

OBJECTIVES: Assess the relationship between clinical diagnosis, state of immunosuppression, mycophenolic acid (MPA) plasma trough levels (MPACmin), and mycophenolate mofetil (MMF) dosage in renal transplant recipients. MATERIALS AND METHODS: MPACmin were determined in 30 kidney transplant patients, of whom 7 exhibited biopsy-proven acute rejection. The remaining 23 had normal graft function. Graft outcome, defined by clinical diagnosis and serum creatinine level, was compared according to MPACmin, MMF dosage, and total lymphocyte count (LC). RESULTS: Patients with acute rejection had similar MPACmin (2.4 +/- 1.7 microg/mL), MMF dosages (1.7 +/- 0.5 g), and LCs (0.001165 +/- 0.0040 x 10(9)/L) when compared with normal patients (2.2 +/- 0.7 microg/mL, 1.7 +/- 0.4 g and 0.001160 +/- 0.00527 x 10(9)/L) respectively. Rejection rates were comparable irrespective of MPACmin)ranges and higher in those receiving the 1-g dose (30%) when compared with those receiving 1.5-g and 2-g doses (12.5% and 11.7%). No relationship was observed between MPACmin and MMF doses, and neither parameter correlated with LC. CONCLUSIONS: These results suggest that MPACmin is a poor correlate of clinical outcome and state of immunosuppression. Although the usually recommended dosage of MMF (2 g) may be associated with acute rejection, low-dose MMF (1 g) seems to constitute a higher risk.

Dermopathic changes in hypozincemia.

In seven patients with chronic debilitating gastrointestinal disease who were being given total parenteral nutrition using L-amino acids and concentrated dextrose solution, severe hypozincemia (less than 60 micrograms/dL) developed with characteristic skin lesions and alopecia. The lesions were similar to seborrheic dermatitis, and they occurred in areas of high sebaceous gland concentration. Hyperkeratotic lesions were also seen on the extensor surfaces of large joints. The skin lesions and alopecia disappeared when serum zinc values were raised to levels above 60 micrograms/dL, with appropriate zinc sulfate replacement. A hypothesis on the etiology and clinical manifestations is presented.

A comprehensive, barcoded system for the management of animal information in a research facility.

The authors describe an easy-to-use barcode-based animal tracking system that has improved record keeping and data retrieval and proved instrumental in the containment of an outbreak.

Radioactivity and fluoride contamination derived from a phosphate fertilizer plant in Egypt.

The environmental pollution caused by the wastewater from a phosphate fertilizer plant in Egypt was investigated. The concentrations of radionuclides and fluoride in phosphate fertilizer (raw materials, end products and by-products) and other types of fertilizer samples were measured. The concentrations of these elements were also measured in environmental samples (water, sediment and plant) collected from the proximity of outlet of wastewater discharge pipes of the phosphate fertilizer company. The fluoride concentration was ranged from 0.03 to 0.25mg/g, 0.002 to 0.006mg/g, 0.42 to 1.88mg/g and 0.44 to 7.3mg/l for phosphate fertilizer, other types of fertilizer, sediment and water samples, respectively. The activity concentrations of (226)Ra were ranged from 244 to 1312Bq/kg, 0.6 to 12.1Bq/kg, 15.4 to 33.8Bq/kg, 0.06 to 1.3Bq/l and 8.9 to 17.3Bq/kg for phosphate fertilizer, other types of fertilizer, sediment, water and plant samples, respectively. The (232)Th activity concentrations were ranged from 0.7 to 24Bq/kg, 0.7 to 14.5Bq/kg, 10.4 to 19.3Bq/kg, 0.02 to 0.16Bq/l and 2.0 to 29.8Bq/kg for these samples, respectively. Also, the (40)K activity concentrations were ranged from 2.1 to 1.4Bq/kg, 2.1 to 5313Bq/kg, 128 to 281Bq/kg, 0.14 to 0.6Bq/l and 686 to 977Bq/kg for these samples, respectively. Low content of (137)Cs was determined in only two phosphate fertilizer samples (F2 and F3; mean 1.3Bq/kg) and in most of sediment samples (with range 1.0-2.4Bq/kg). The radium equivalent, as a radiation hazard index, was ranged from 284 to 1316, 9.6 to 432 and 47 to 70Bq/kg for phosphate fertilizer, other types of fertilizer and sediment samples, respectively. The results indicated that the wastewater polluted with fluoride produced from the phosphate fertilizer company may be affecting the environment. The radioactivity content measurements indicated that the environment may be slightly affected with low concentrations of (226)Ra and (232)Th isotopes due to the discharged wastewater from the phosphate fertilizer industry. On the other hand, the results of comparison studies for radioactivity concentrations are also presented and discussed.

The venous drainage of the pancreas.

With the aim of clarifying certain contradictory aspects of the description of the venous drainage of the pancreas, a review of the literature and an anatomic study were carried out. Fifty duodeno-pancreatic blocks were studied by the injection-corrosion technique, of which 45 were available for study of the right pancreas and 37 for that of the left pancreas. The venous drainage of the duodeno-pancreas is effected via two territories: a posterosuperior and an anteroinferior, the former draining toward the portal v. and the second into the superior mesenteric v. The borderline between the two is represented by the inferior posterior pancreatico-duodenal (IPPD) v. Four veins ensure duodeno-pancreatic drainage: the superior anterior, inferior anterior, superior posterior and inferior posterior pancreatico-duodenal vv. (SAPD, IAPD, SPPD and IPPD). The major vein of the ventral aspect is the SAPD; that of the dorsal aspect is the SPPD. Two arches, anterior and posterior, were found in the majority of cases. The left pancreas drains into the splenic v. via several collateral branches. Other veins participate in the venous drainage of the isthmus, body and tail of the pancreas, including the inferior or transverse pancreatic v.

Extrahepatic biliary steering-wheel trauma simulating pancreatic carcinoma--a dilemma in management.

A case report of extrahepatic common bile duct injury manifesting 3 weeks after a car accident, which resulted in a submucosal hematoma simulating bile duct carcinoma. Following operative placement of a T-tube the hematoma in the common bile duct resolved. The case presented supports the theory that the injury is caused by the effect of a shearing force on the inelastic common bile duct (5).

Obstructive, pseudo-obstructive and enteropathic syndromes after jejunoileal bypass.

We have encountered two patients with volvulus of the small intestine at the ileocolic anastomosis, occurring after jejunoileal bypass. This uncommon complication is generally seen many months after bypass and may be difficult to diagnose. Barium enema examination was helpful in one patient. If there are acute, severe abdominal symptoms, mechanical obstruction and early operation should be considered. Attention has been called to other intestinal syndromes with obstructive features developing after jejunoileal bypass, and these have been compared.

Poor prognosis of patients with intra-abdominal sepsis and hypouricemia.

With uric acid levels of 0.4 to 3.0 milligrams per cent, hypouricemia was noted in 17 patients with intra-abdominal sepsis. This was associated with a fivefold to sixteenfold increase in the urate clearance and uric acid to creatinine clearance ratios. The number of deaths in the 17 patients with hypouricemia is 14 versus 20 for the overall group of 111 patients studied. Two patients had a reversal of the serum uric acid, 24 hour urine uric acid output and uric acid to creatinine clearance ratio, with drainage of the intra-abdominal sepsis. Hypouricemia seems to indicate a poor prognosis in patients with intra-abdominal sepsis.

HLA-DR antigens and phenotypes in Dutch coeliac children and their families.

In a study on the HLA-DR antigens and phenotypes in a series of Dutch coeliac children and their first-degree relatives, the B-cell antigens of 36 unrelated coeliac children, 110 first-degree relatives of 33 of them, and 201 controls were typed with the two-colour fluorescence test. The most frequent antigen was HLA-DR3 (69%), followed by DR7 (36%). The distribution of DR phenotypes showed that the most frequent was DR3/other DR (25%), followed by DR3/DR7 (17%), DR3/DR4 (14%), and DR3/DR3 (14%). However, due to the frequency of certain antigens in the controls, only phenotypes DR3/DR3 (relative risk = 6.2), DR3/DR7 (relative risk = 6.4), and DR3/DR4 (relative risk = 6.2) were significantly associated with CD. The family study confirmed the segregation of the disease with phenotypes DR3/DR3 and DR3/DR7. The present results show that the association between CD and phenotypes DR3/DR3 and DR3/DR7 is not an exclusive characteristic of Southern coeliac children.

Insulin as a mediator of hepatic glucose uptake in the conscious dog.

The aim of this study was to determine whether a physiological increment in plasma insulin could promote substantial hepatic glucose uptake in response to hyperglycemia brought about by intravenous glucose infusion in the conscious dog. To accomplish this, the plasma glucose level was doubled by glucose infusion into 36-h fasted dogs maintained on somatostatin, basal glucagon, and basal or elevated intraportal insulin infusions. In the group with basal glucagon levels and modest hyperinsulinemia (33 +/- 2 micro U/ml), the acute induction of hyperglycemia (mean increment of 120 mg/dl) caused marked net hepatic glucose uptake (3.7 +/- 0.5 mg . kg-1 . min-1). In contrast, similar hyperglycemia brought about in the presence of basal glucagon and basal insulin levels described net hepatic glucose output in 56%, but did not cause net hepatic glucose uptake. The length of fast was not crucial to the response because similar signals (insulin, 38 +/- 6 micro U/ml; glucose increment, 127 mg/dl) promoted identical net hepatic glucose uptake (3.8 +/- 0.6 mg . kg-1 . min-1) in dogs fasted for only 16 h. In conclusion, in the conscious dog, a) physiologic increments in plasma insulin have a marked effect on the ability of hyperglycemia to stimulate net hepatic glucose uptake, and b) it is not necessary to administer glucose orally to promote substantial net hepatic glucose uptake.

Short-term and long-term ethanol administration inhibits the placental uptake and transport of valine in rats.

Ethanol ingestion during pregnancy causes a pattern of fetal/neonatal dysfunction called the FAS. The effects of short- and long-term ethanol ingestion on the placental uptake and maternal-fetal transfer of valine were studied in rats. The in vivo placental uptake and fetal uptake were estimated after injection of 0.04 micromol of 14C-valine intravenously on day 20 of gestation in Sprague-Dawley rats. Short-term ethanol ingestion (4 gm/kg) caused a significant reduction in the placental uptake of 14C-valine by 33%, 60%, and 30%, and 31% at 2.5, 5, 10, and 15 min after valine administration, respectively (p less than 0.01), and a similar significant reduction occurred in the fetal uptake of 14C-valine (p less than 0.01). Long-term ethanol ingestion prior to and throughout gestation resulted in a 47% reduction in placental valine uptake (p less than 0.01) and a 46% reduction in fetal valine uptake (p less than 0.01). Long-term ethanol feeding from day 4 to day 20 of gestation caused a 32% reduction in placental valine uptake (p less than 0.01) and a 26% reduction in fetal valine uptake (p less than 0.01). We conclude that both short- and long-term ingestion of ethanol inhibit the placental uptake and maternal-fetal transfer of an essential amino acid--valine. An alteration of placental function may contribute to the pathogenesis of the FAS.