30852659
Microthermogravimetry using a microcantilever hot plate with integrated temperature-compensated piezoresistive strain sensors.
This paper reports thermogravimetric analysis of nanogram samples of paraffin using a microcantilever hot plate. The microcantilever hot plate has an integrated temperature-controlled heater and integrated temperature-compensated strain-sensing piezoresistors. The microcantilever vibration amplitude was measured using either a laser and a position sensitive photodiode, or using the piezoresistors. The cantilever resonance was measured as the cantilever was heated, such that the analyte mass could be measured as a function of temperature. Both optical and piezoresistive methods were employed to generate thermogravimetric curves for analytes in the range of 1-3 ng, and the results of the two methods compared well.
36285154
Microcantilever actuation via periodic internal heating.
This paper reports electrothermal actuation of silicon microcantilevers having integrated resistive heaters. Periodic electrical excitation induced periodic resistive heating in the cantilever, while the cantilever deflection was monitored with a photodetector. Excitation was either at the cantilever resonant frequency, f(0), f(0)/2, or f(0)/3. When the time averaged maximum cantilever temperature was 174 degrees C, the cantilever out-of-plane actuation amplitude was 484 nm near the cantilever resonance frequency of 24.9 kHz. This actuation was sufficiently large to operate the cantilever in intermittent contact mode and scan a calibration grating of height of 20 nm.
21814270
Electrical and thermal coupling to a single-wall carbon nanotube device using an electrothermal nanoprobe.
We utilize a multifunctional atomic force microscope (AFM) cantilever applying highly localized temperature and electric fields to interrogate transport in single-wall carbon nanotube field-effect transistors (CNTFETs). The probe can be operated either in contact with the CNT, in intermittent contact, or as a Kelvin probe, and can independently control the electric field, mechanical force, and temperature applied to the CNT. We modulate current flow in the CNT with tip-applied electric field, and find this field-effect depends upon both cantilever heating and CNT self-heating. CNT transport is also investigated with AFM tip temperature up to 1170 degrees C. Tip-CNT thermal resistance is estimated at 1.6 x 10(7) K/W and decreases with increasing temperature. Threshold force (<100 nN) for reliable contact mode imaging is extracted and used to determine set points for nanotube manipulation, such as displacement or cutting. The ability to measure thermal coupling to a single-molecule electronic device could offer new insights into nanoelectronic devices.
38537498
Gallbladder damage control: compromised procedure for compromised patients
BackgroundThe objective of this study was to analyze a population-based database for (1) recent 9-year trends in utilization of partial cholecystectomy (PC), laparoscopic PC, and trocar cholecystostomy (TC), (2) demographics, associated diagnoses, and hospital characteristics, and (3) relevant inpatient outcomes.MethodsRetrospective cohort analysis of the Nationwide Inpatient Sample (NIS) files from 2000 to 2008 was performed. For the purposes of the study, gallbladder damage control was defined as PC, laparoscopic PC, and TC.ResultsA national estimate of 10,872 gallbladder damage control cases was obtained. Procedures performed included PC (47.8 %), laparoscopic PC (27.2 %), TC (25.3 %), and intraoperative cholangiogram (IOC) (19.7 %). A total of 1,479 (13.6 %) postoperative complications were identified, including pulmonary complications (4.3 %), hemorrhage/hematoma/seroma (3.4 %), and accidental puncture or laceration during procedure (3.3 %). Common bile duct injury occurred in 3.3 % overall. Hospital types included nonteaching (82.1 %) and urban (67.8 %), with regional variations of 42.1 % from the South and 45.2 % from the West. Inpatient outcomes included mean length of stay of 11.4 (0.16 SEM) days, mean total hospital charge of $71,296.69 ($1,106.03 SEM), 7.4 % mortality, and 16.8 % discharge to skilled nursing facility. Multivariate logistic regression analysis identified independent risk variables for common bile duct injury: teaching hospitals (OR = 1.517, CI = 1.155–1.991, P = 0.003). IOC (OR = 2.030, CI = 1.590–2.591, P < 0.001) was a commonly associated procedure in the setting of common bile duct injury.ConclusionVarious circumstances may require gallbladder damage control with PC and TC. Postoperative complications and common bile duct injury remain significantly high despite limited resection, and the teaching status of the hospital is associated with CBD injury. High morbidity and mortality of gallbladder damage control may reflect both the compromised nature of the procedures and multiple comorbidities.
24325594
Population structure of and mycotoxin production by Fusarium graminearum from maize in South Korea.
Fusarium graminearum (Gibberella zeae) is an important pathogen of wheat, maize, barley, and rice in South Korea, and harvested grain often is contaminated with trichothecenes such as deoxynivalenol and nivalenol. In this study, we examined 568 isolates of F. graminearum collected from maize at eight locations in South Korea. We used amplified fragment length polymorphisms (AFLPs) to identify four lineages (2, 3, 6, and 7); lineage 7 was the most common (75%), followed by lineage 6 (12%), lineage 3 (12%), and lineage 2 (1%). The genetic identity among populations was high (>0.98), and the effective migration rate between locations was higher than that between lineages. Female fertility varied by lineage: all lineage 7 isolates were fertile, while 70%, 26%, and 14% of the isolates in lineages 6, 3, and 2, respectively, were fertile. All lineage 3 and lineage 7 isolates produced deoxynivalenol, whereas most lineage 2 and 6 isolates produced nivalenol. Genotypic diversity in lineage 3 and lineage 6 populations is similar to that found in previously described Korean rice populations, but genotypic diversity in lineage 7 is much lower, even though similar levels of gene flow occur between lineage 7 populations. We conclude that lineage 7 was relatively recently introduced into South Korea, perhaps accompanying imported maize seeds.
23818831
The critical-size supraalveolar peri-implant defect model: reproducibility in histometric data acquisition of alveolar bone formation and osseointegration.
OBJECTIVE
The objective of this report is to present the reproducibility of outcomes assessments in the Critical-Size Supraalveolar Peri-Implant Defect Model.


MATERIALS AND METHODS
Two examiners without specific experience in histological analysis and one experienced examiner performed the histometric evaluation. A comprehensive training program in data acquisition and histological analysis was established, the inexperienced examiners underwent approximately 12 h of training over multiple sessions. A custom-designed image analysis software macro and a computer-based image system were used to analyse digital images generated by a microscope camera system. Nine parameters for newly formed and resident bone were evaluated. Examiners performed histometric analysis using 36 histologic sections selected from critical-size supraalveolar peri-implant defects in 12 male Hound Labrador Mongrel dogs. Buccal and lingual measurements were performed in 72 sites. Intra- and inter-examiner reproducibility were evaluated using the concordance correlation coefficient (CCC) and means +/- SD of the differences. Systematic errors were evaluated using an F-test for equality of means and variances.


RESULTS
Intra-examiner reproducibility was high for all parameters evaluated, the lowest CCC observed being 0.87. Inter-examiner reproducibility was also high, most CCCs exceeding 0.90. Minor systematic errors for intra- and inter-examiner comparisons were occasionally observed. The results imply a high temporal stability because recordings were performed 3 months apart. Measurement errors were stable throughout the range of observations for all parameters.


CONCLUSIONS
High examiner reproducibility and temporal stability can be achieved for histometric data acquisition using the Critical-Size Supraalveolar Peri-Implant Defect Model. Examiner reproducibility should be routinely assessed, reported, and accounted for to assure the quality of evidence generated by preclinical studies.
8445969
CIP2A expression is associated with synovial hyperplasia and invasive function of fibroblast-like synoviocytes in rheumatoid arthritis
Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a recently identified oncoprotein that leads to cellular proliferation in cancer cells. We aim to investigate CIP2A expression in fibroblast-like synoviocytes (FLS) and its association with the histopathological grade of synovitis and the invasive function of FLS in rheumatoid arthritis (RA). CIP2A protein expression was measured in 8 RA FLS and 8 OA FLS using Western blot analysis. CIP2A mRNA expression from 19 RA FLS and 7 OA FLS was measured using real-time PCR. Synovitis score of RA FLS-matched synovial tissues was semiquantitatively measured by two independent pathologists. An in vitro cell invasion assay was performed using RA FLS treated with CIP2A small interfering RNA (siRNA) or with control vector. Western blot analysis showed that CIP2A is more frequently overexpressed in RA FLS compared with OA FLS. CIP2A mRNA expression was higher in RA FLS compared with those in OA FLS, but did not reach statistical significance (P = 0.076). In RA, total synovitis score was strongly correlated with FLS CIP2A mRNA expression (rs = 0.849, P = 0.043). TNF-α treatment induced a robust increase in the invasive function of control FLS (P = 0.0021), but no significant effect was observed in CIP2A siRNA-treated FLS. Our data demonstrate that CIP2A expression is closely associated with the histopathological score of synovitis and invasive function of FLS in RA. These results suggest that CIP2A may play a critical role in the destructive process in RA and warrant further investigation of CIP2A as a therapeutic target.
7202726
Improved shim method based on the minimization of the maximum off-resonance frequency for balanced steady-state free precession (bSSFP).
In this work, a shim method that minimizes the maximum off-resonance frequency (min-max shim) in balanced steady-state free precession (bSSFP) is tested for brain imaging at 3T with constant and linear shim terms. The method demonstrates improvement of spatial coverage and banding artifact reduction over standard least-squares shimming. In addition, a new method (modified min-max shim) is introduced. This method reduces boundary band regions where the artifact is inevitable due to the excessive off-resonance frequency distribution. In comparison to standard least-squares shimming, the min-max based shim method either eliminates or reduces the size of banding artifacts. The method can be used to increase the signal-to-noise ratio (SNR) in bSSFP imaging or to increase the functional contrast in bSSFP functional MRI (fMRI) by allowing a longer usable repetition time (TR).