Low-power Field Research Articles

Experimental investigation of the effects of variable expanding channel on the performance of a low-power cusped field thruster

Due to a special magnetic field structure, the multi-cusped field thruster shows advantages of low wall erosion, low noise and high thrust density over a wide range of thrust. In this paper, expanding discharge channels are employed to make up for deficiencies on the range of thrust and plume divergence, which often emerges in conventional straight cylindrical channels. Three thruster geometries are fabricated with different expanding-angle channels, and a group of experiments are carried out to find out their influence on the performance and discharge characteristics of the thruster. A retarding potential analyzer and a Faraday probe are employed to analyze the structures of the plume in these three models. The results show that when the thrusters operate at low mass flow rate, the gradually-expanding channels exhibit lower propellant utilization and lower overall performance by amounts not exceeding 44.8% in ionization rate and 19.5% in anode efficiency, respectively. But the weakening of magnetic field intensity near the exit of expanding channels leads to an extended thrust throttling ability, a smaller plume divergence angle, and a relatively larger stable operating space without mode converting and the consequent performance degradation.

Verification of the methodology for evaluating tumor-infiltrating lymphocytes in colorectal cancer.

BackgroundThe density of tumor-infiltrating lymphocytes (TILs) have been reported to reflect antitumor immune response and correlate with prognosis in malignancy. However, the methodology for evaluating the density of TILs by an immunohistochemical analysis differs among reports. The aim of this study was to verify the methodology for evaluating the density of TILs by immunohistochemical analysis and thereby identify the optimum methodology in clinical setting.MethodsThree-hundred-thirteen patients who underwent curative operation for stage II/III colorectal cancer were enrolled. We retrospectively examined the density of TILs using immunohistochemical staining according to each method as follows: 1) subset of lymphocytes (i.e. CD4+/CD8+), 2) selected fields (i.e. at random or focusing on hot spots), 3) location in low-power field (i.e. the invasive margin [TILsIM] or the center of the tumor [TILsCT] or the surface of the tumor [TILsST]), and 4) location in high-power field (i.e. in tumor stroma [sTILs] or intra-tumor cells [iTILs] or total TILs [tTILs: sTILs+iTILs]). We then assessed the prognostic value of the density of TILsIM evaluated as described above. We also evaluated the correlation between the density of TILsIM and that of TILsCT/TILsST.ResultsOnly the densities of CD8+sTILsIM and CD8+tTILsIM evaluated in randomly selected fields were significantly associated with the survival. Furthermore, the density of CD8+TILsIM was significantly associated with that of CD8+TILsCT and CD8+TILsST.ConclusionsWe concluded that best and easiest way to evaluate the density of TILs in the clinical setting may be to assess the density of CD8+tTILsIM in randomly selected fields.

A Low-Power Wearable Stand-Alone Tongue Drive System for People With Severe Disabilities.

This paper presents a low-power stand-alone tongue drive system (sTDS) used for individuals with severe disabilities to potentially control their environment such as computer, smartphone, and wheelchair using their voluntary tongue movements. A low-power local processor is proposed, which can perform signal processing to convert raw magnetic sensor signals to user-defined commands, on the sTDS wearable headset, rather than sending all raw data out to a PC or smartphone. The proposed sTDS significantly reduces the transmitter power consumption and subsequently increases the battery life. Assuming the sTDS user issues one command every 20 ms, the proposed local processor reduces the data volume that needs to be wirelessly transmitted by a factor of 64, from 9.6 to 0.15 kb/s. The proposed processor consists of three main blocks: serial peripheral interface bus for receiving raw data from magnetic sensors, external magnetic interference attenuation to attenuate external magnetic field from the raw magnetic signal, and a machine learning classifier for command detection. A proof-of-concept prototype sTDS has been implemented with a low-power IGLOO-nano field programmable gate array (FPGA), bluetooth low energy, battery and magnetic sensors on a headset, and tested. At clock frequency of 20 MHz, the processor takes 6.6 s and consumes 27 nJ for detecting a command with a detection accuracy of 96.9%. To further reduce power consumption, an application-specified integrated circuit processor for the sTDS is implemented at the postlayout level in 65-nm CMOS technology with 1-V power supply, and it consumes 0.43 mW, which is 10 lower than FPGA power consumption and occupies an area of only 0.016 mm.

Correction: Integration of BiFeO3/La0.7Sr0.3MnO3 heterostructures with III–V semiconductors for low-power non-volatile memory and multiferroic field effect transistors

Correction for ‘Integration of BiFeO3/La0.7Sr0.3MnO3 heterostructures with III–V semiconductors for low-power non-volatile memory and multiferroic field effect transistors’ by Md. Shafiqur Rahman et al., J. Mater. Chem. C, 2016, 4, 10386–10394.

High-Performance Field Emission from a Carbonized Cork.

To broaden the range of application of electron beams, low-power field emitters are needed that are miniature and light. Here, we introduce carbonized cork as a material for field emitters. The light natural cork becomes a graphitic honeycomb upon carbonization, with the honeycomb cell walls 100-200 nm thick and the aspect ratio larger than 100, providing an ideal structure for the field electron emission. Compared to nanocarbon field emitters, the cork emitter produces a high current density and long-term stability with a low turn-on field. The nature of the cork material makes it quite simple to fabricate the emitter. Furthermore, any desired shape of the emitter tailored for the final application can easily be prepared for point, line, or planar emission.

DeSUMOylation of protein kinase B1 inhibits cell proliferation and metastasis of hepatocellular carcinoma

Objective: To investigate the effect of AKT1 deSUMOylation induced by Ubc9 silencing on the proliferation and metastasis of hepatocellular carcinoma (HCC) cells. Methods: The Ubc9 gene was silenced using RNA interference, and the expression levels of Ubc9, SUMO1 and AKT1 protein were detected by Western blot. Cell proliferation and cell cycle was analyzed by MTT and flow cytometry. Wound healing and transwell assays were used to detect the cell migration ability. Furthermore, the xenograft model was established, and tumor growth curves were drawn. The in situ apoptotic rates was measured using TUNEL Apoptosis Assay. The expression of proliferating cell nuclear antigen (PCNA), matrix metalloproteinase (MMP)-2 and MMP-9 were evaluated by immunohistochemical staining. Results: Knockdown of Ubc9 gene significantly decreased the protein expression levels of Ubc9, conjugated SUMO1, free SUMO1 and AKT1 in HCC cells (P<0.05 for all). In control, siR-neg and siR-Ubc9 groups, the cell proliferation indexes were 53.19%, 54.25% and 39.17%, respectively. Moreover, cell migration distance and migrating cells per low power field for all these three groups were (59.47±4.66) μm and 89.44±8.36, (56.56±5.37) μm and 93.84±8.79, as well as (34.57±6.61) μm and 41.67±5.39, respectively. In the xenograft model, the weights of subcutaneous tumors for these three groups were (3.78±0.69) g, (3.72±0.72) g and (2.09±0.61) g, respectively. The corresponding apoptotic cell rates were (7.79±2.21)%, (6.45±2.48)% and (33.59±5.44)%, respectively. The expression levels of PCNA, MMP-2 and MMP-9 protein were significantly decreased in siR-Ubc9 group (P<0.05). Conclusions: Ubc9 silencing in HCC cells induces AKT1 deSUMOylation, and then inhibits the proliferation and metastasis. These results provide a new therapeutic strategy for liver cancer in the future.

Diagnostic value of sputum smear and simplified clinical pulmonary infection score of ventilator associated pneumonia in the early stage

Objective To explore the diagnostic value of sputum smear coupled with simplified clinical pulmonary infection score (CPIS) of ventilator associated pneumonia (VAP) in the early stage. Methods A cohort of 59 consecutive patients with VAP admitted in Intensive Care Unit from June, 2014 to June, 2016 were enrolled for a prospective and observational study. Concurrently, another 59 patients without pulmonary infection undergone mechanical ventilation over 48 hrs, were assigned into the control group. The criteria of exclusion were patients with pulmonary malignancies, autoimmune diseases and immunodeficiency. APACHEⅡscores of all patients were recorded. All patients’ inferior airway sputum which met the criteria was taken to make a validated sputum smear(i.e. polymorphonuclear leukocyte >25 and squamous epithelial cell <10 per low-power field) for Gram stain and culture on the admission day. Meanwhile, simplified CPIS were calculated. Data were statistically processed by SPSS 15.0, enumeration data were statistically analyzed by Chi-Square test, and measurement data were represented as Mean±SD. The significant differences in characteristics between two groups were analyzed by independent t test, and P<0.05 was considered statistically significant. As positive sputum smear and simplified CPIS≥5 were set respectively as a positive screening criterion, sensitivity, specificity, positive predictive value and negative predictive value of each marker and combined markers were calculated. Results There were no significant differences in demographics and clinical features (including age, sex, APACHEⅡscores) of patients in VAP and non-VAP patients (P>0.05). The rates of bacteria detected were Gram-negative [44.1% (26/59)], Gram-positive [40.6% (24/59)], none [10.2% (6/59)] and both [5.1% (3/59)] bacteria in VAP group, while [39.0% (23/59)], [30.5% (18/59)], [27.1% (16/59)] and [3.4% (2/59)] were found in non-VAP group correspondingly. There were no significant differences in the percentages of different bacteria in sputum smear between two groups(P>0.05). The values of diagnostic sensitivity of sputum smear and sputum smear coupled with simplified CPIS were 89.8% and 84.7%; the specificity were 27.1% and 79.7%; the positive predictive values were 55.2% and 80.6%; and the negative predictive values were 72.7% and 83.9%, respectively. Conclusions No matter the ventilated patients suffered VAP or not, bacteria might be detected from their lower respiratory tracts. Sputum smear could not be taken as an exclusively diagnostic evidence. While sputum smear coupled with simplified CPIS might improve the diagnostic efficacy of VAP, and provide the guildlines of appropriate choice of antibiotics employed in the early stage. Key words: Sputum smear and gram stain; Clinical pulmonary infection score; Ventilator associated pneumonia

Diffuse Eosinophilic Gastrointestinal Disease

We describe a 26-year-old female with one year of intermittent abdominal pain and vomiting, found to have diffuse eosinophilic infiltrate of her gastrointestinal tract unresponsive to steroids. A 26-year-old female with a history of multiple food and seasonal allergies presented with one year of nausea, vomiting, diarrhea, abdominal pain, and weight loss. Labs were significant for anemia and peripheral eosinophilia of 10.5%. Remaining labs, including inflammatory markers and stool studies, were normal. Endoscopy revealed esophageal exudates and multiple non-bleeding gastric ulcers with biopsies showing intraepithelial eosinophils over 100 eos/hpf. Colonoscopy revealed non-specific focal ileitis and random colon biopsies showed focal areas of 50-60 eos/hpf. Video capsule endoscopy only showed nonspecific findings. Treatment with intravenous and oral steroids was not tolerated due to increased pain. Cromolyn, montelukast, antihistamines and enteral steroids were tried with minimal improvement. The patient was started on total parenteral nutrition as additional therapy is evaluated. Eosinophilic gastrointestinal disorders (EGIDs) are remarkably rare. Estimated prevalences of eosinophilic esophagitis, gastritis, gastroenteritis, and colitis are 55, 6.3, 8.4 and 3.3/100,000, respectively.1,2 Our patient is unique in that she has eosinophilic esophagitis, gastritis, enteritis, and colitis. Common EGID symptoms include abdominal pain, nausea, vomiting, weight loss, and diarrhea.3 Additionally, coexisting allergic conditions are seen with approximately 38.5-45.6% of eosinophilic gastritis, gastroenteritis, and colitis patients.2 There are no specific treatment guidelines for EGIDs. Prednisone is considered the mainstay treatment with most studies showing 90% remission.3 Our patient, however, did not respond to leukotriene receptor antagonists, mast cell stabilizers, systemic or enteral steroid treatments. Based on few case reports, remaining options include immunosuppression, interleukin-5 antagonists or anti-IgE. EGID subtypes are rare with several treatment options available. Our case is unique in its diffuse gastrointestinal involvement and lack of response to traditional therapy. With a paucity of data and no proven strategies for treatment, our cases poses an unusual therapeutic challenge.Figure: Antral Ulcer (Low Power Field).Figure: Esophagus (High Power Field).

Improvement of experimental characteristics of pipeline volume materials in microwave electromagnetic field

The change in the performance characteristics of sealing and anti friction materials of pipeline armature exposed to a microwave electromagnetic field of low specific power 4-5 W/cm3 was studied. The dimensional and mass fluoroplastics and the change in the compliance of the sealing rubber were evaluated. It was established that the treatment in a microwave electromagnetic field with a frequency of 2,450 MHz with a specific power of 4-5 W/cm3 for 4 minutes ensures a reduction in the size and mass wear upon contact. Besides, the compliance of the rubber increases by 20-64 %, depending on the degree of deformation of the counter-body — by 55 and 25 %. After microwave treatment in a similar mode, the malleability of the rubber increases by 20-64 %, depending on the degree of deformation.

Diagnostic and Management Challenges Associated With Vulvar Crohnʼs Disease

Crohn's disease(CD) is an IBD with extra intestinal manifestations such as arthritis, uveitis, erythema nodosum. Crohn's disease of the vulva is a rare and under recognized condition, particularly because it may not involve GI tract. The diagnosis and treatment of this condition remains a challenge. We present a case of Vulvar Crohn's which has been an extremely difficult case to manage. Our patient is a 29 y/o female with 10 year h/o vulvar Crohn's disease presenting as painful fissures, perirectal and labial masses. On physical exam, there was erythema, induration and severe edema of labia majora, minora and perianal area. She underwent biopsy of the lesions which was confirmed to be Crohn's disease. Even though she had no GI symptoms, she underwent colonoscopy to determine the extent of her disease and it was normal. Patient was tried on several medications including metronidazole, steroids, 6-MP, infliximab, adalimumab, methotrexate, azathioprine, certolizumab,ustekinumab and vedolizumab. However, she failed to respond to any of these therapies. Patient was referred to plastic surgery for partial vulvectomy, biopsy of which showed high grade vulvar intraepithelial neoplasia (VIN) in addition to Crohn's (dermal chronic inflammation with granulomas). She was then referred to colorectal surgery for management of perianal disease, and gynecology for evaluation of VIN. She also underwent excision of anal skin tags and anal mapping, with pathology demonstrating positive P16 in squamous epithelium consistent with high grade AIN. Vulvar Crohn's is an under-recognized condition with about 100 cases reported to date. It can occur by direct extension from perianal region or by metastatic spread from bowel. Vulvar CD may precede intestinal involvement in about 25% of cases. It usually presents with edema, ulcerations and fissures of the vulva. Patients may be asymptomatic or present with pain, pruritis, discharge and dyspareunia. Diagnosis requires a high degree of suspicion as it could be mistaken for other conditions like infections, sarcoidosis etc. Diagnosis is confirmed by biopsy. Treatment remains a challenge and no treatment guidelines exist. A multidisciplinary approach is recommended and medications including steroids, thiopurines, TNF-α antagonists could be used. However, patients may not respond to any medications and surgery remains an option. Clinicians must be astute to consider neoplasia in this situation, as was seen in our patient.Figure: Microscopic findings of the epiglottis biopsy demonstrating in the high- and low-power fields ulcerated squamous mucosa with chronic inflammatory changes.

Correlation between histological and ultrasonographic findings of soft tissue tumors: To verify the possibility of cell-like resolution in ultrasonography

BackgroundThe purpose of this study is to test the possibility of obtained cell-like resolution in soft tissue tumors on the basis of ultrasound echotexture. MethodsThis is a prospective study consisting of 57 patients (29 females and 28 males, age range: 9–83 years, average age: 44.5 years) with palpable soft tissue mass, referred from the Departments of Orthopedics and Oncology for ultrasound (US)-guided biopsy. The study was approved by the institutional review board (IRB) of our hospital. Ultrasonographic images were recorded by still imaging in the biopsy tract in each biopsy session. Equipment included curvilinear and linear array probes. After biopsy, a radiologist and a pathologist correlated the US image and the observations regarding the histology of the tissue specimen in low-power (40 × magnification) and high-power (100–400 × magnification) fields. ResultsThe histologic results included 22 benign and 35 malignant lesions. The echotexture of the soft tissue tumors correlated well with the cellular distribution and arrangement: the greater the number of cells and the more regular their arrangement as seen histologically, the greater is the hypoechogenicity on the ultrasound. The echogenicity of the soft tissue tumor also correlated well with the presence of fat cells, hemorrhage, cartilage, and osteoid tissue, all of which cause an increase in echogenicity. ConclusionThis study showed that the echotexture of soft tissue tumors can predict some details of cellular histology.

Tuning of Multiple Parameters With a BIST System

This paper presents a low-power built-in self-test system to compensate for mismatch and variations in CMOS IC. The system is designed and compiled on a low-power field programmable analog array (FPAA) fabricated on a 350-nm CMOS process. A second-order bandpass filter is used as a device under test. A set of 12 parallel filter banks are compiled on three different FPAA chips and compensated for local mismatch and variations in the bias current, and mismatch in parasitic and routing capacitances. The bandpass filters are biased in subthreshold regime and the system of 12 parallel filter banks consumes a power of $7.072~\mu \text{W}$ . The proposed tuning algorithm reduces variation in center frequency to 5.07% compared with a variation of 10.16% when they are not tuned, variation in quality factor to 8.52% from 13.86%, and variation in the gain at the center frequency to 3.83% from 21.04%. These values are deviation of the parameters from its mean for the data taken from three different FPAA chips fabricated on the same wafer.

Mechanism of long non-coding RNA-metastasis associated lung adenocarcinoma transcript 1 induced invasion and metastasis of esophageal cancer cell EC-109

Objective: To investigate the effect and mechanism of long non-coding RNA-metastasis associated lung adenocarcinoma transcript 1, (LncRNA-MALAT1) on invasion and metastasis of esophageal cancer cell EC-109. Methods: EC-109 cells were transfected with lentiviral vector carrying short hairpin RNA of MALAT1( shRNA-MALAT1) or a nonspecific shRNA control (shRNA-control). The expressions of MALAT1, microRNA-200a, ZEB1 and ZEB2 were detected by qRT-PCR. The effect of shRNA-MALAT1 on invasion of EC-109 cells was determined by transwell assay. The expressions of components of epithelial-msenchymal transition pathway in EC-109 cells were determined by immunofluorescence array and western blotting. The expression relationship between MALAT1 and miR-200a in EC-109 cells was detected by dual-luciferase reporter assay. Results: The result of qRT-PCR showed that the expressions levels of MALAT1, ZEB1 and ZEB2 in shRNA-MALAT1 group were 0.43±0.06, 0.64±0.04 and 0.51±0.04, respectively, significantly lower than 0.97±0.08, 1.06±0.07 and 0.98±0.05 in shRNA-control group and 1 in control group, respectively(all P<0.05). Transwell assay showed that the number of invaded cells in shRNA MALAT1 group was (96.81±10.43) per low-power field, markedly lower than that of (278.44±13.28) per low-power field in shRNA-control group (P<0.01). Immunofluorescence staining and Western blotting showed that MALAT1 downregulation significantly reduced the expressions of proteins related to EMT signal pathway in EC-109 cells.Dual luciferase reporter assay showed that compared to negative control, the activities of luciferase reporter in EC-109 cells co-transfected with pmirGLO-MALAT1-wt and miR-200a were significantly down-regulated. While co-transfected pmirGLO-MALAT1-mut with miR-200a mimics had no effect on the luciferase reporter activities of MALAT1. Conclusion: LncRNA MALAT1 functions as a competing endogenous RNA to regulate the expressions of ZEB1 and ZEB2 by sponging miR-200a and promotes invasion and migration of esophageal cancer cells through inducing epithelial-mesenchymal transition.

Microscopic Analysis and Quality Assessment of Induced Sputum From Children With Pneumonia in the PERCH Study.

Background.It is standard practice for laboratories to assess the cellular quality of expectorated sputum specimens to check that they originated from the lower respiratory tract. The presence of low numbers of squamous epithelial cells (SECs) and high numbers of polymorphonuclear (PMN) cells are regarded as indicative of a lower respiratory tract specimen. However, these quality ratings have never been evaluated for induced sputum specimens from children with suspected pneumonia.Methods.We evaluated induced sputum Gram stain smears and cultures from hospitalized children aged 1–59 months enrolled in a large study of community-acquired pneumonia. We hypothesized that a specimen representative of the lower respiratory tract will contain smaller quantities of oropharyngeal flora and be more likely to have a predominance of potential pathogens compared to a specimen containing mainly saliva. The prevalence of potential pathogens cultured from induced sputum specimens and quantity of oropharyngeal flora were compared for different quantities of SECs and PMNs.Results.Of 3772 induced sputum specimens, 2608 (69%) had <10 SECs per low-power field (LPF) and 2350 (62%) had >25 PMNs per LPF, measures traditionally associated with specimens from the lower respiratory tract in adults. Using isolation of low quantities of oropharyngeal flora and higher prevalence of potential pathogens as markers of higher quality, <10 SECs per LPF (but not >25 PMNs per LPF) was the microscopic variable most associated with high quality of induced sputum.Conclusions.Quantity of SECs may be a useful quality measure of induced sputum from young children with pneumonia.

A non-contrast CMR index for assessing myocardial fibrosis

PurposeSafe, sensitive, and non-invasive imaging methods to assess the presence, extent, and turnover of myocardial fibrosis are needed for early stratification of risk in patients who might develop heart failure after myocardial infarction. We describe a non-contrast cardiac magnetic resonance (CMR) approach for sensitive detection of myocardial fibrosis using a canine model of myocardial infarction and reperfusion. MethodsSeven dogs had coronary thrombotic occlusion of the left anterior descending coronary arteries followed by fibrinolytic reperfusion. CMR studies were performed at 7days after reperfusion. A CMR spin-locking T1ρ mapping sequence was used to acquire T1ρ dispersion data with spin-lock frequencies of 0 and 511Hz. A fibrosis index map was derived on a pixel-by-pixel basis. CMR native T1 mapping, first-pass myocardial perfusion imaging, and post-contrast late gadolinium enhancement imaging were also performed for assessing myocardial ischemia and fibrosis. Hearts were dissected after CMR for histopathological staining and two myocardial tissue segments from the septal regions of adjacent left ventricular slices were qualitatively assessed to grade the extent of myocardial fibrosis. ResultsHistopathology of 14 myocardial tissue segments from septal regions was graded as grade 1 (fibrosis area, <20% of a low power field, n=9), grade 2 (fibrosis area, 20–50% of field, n=4), or grade 3 (fibrosis area, >50% of field, n=1). A dramatic difference in fibrosis index (183%, P<0.001) was observed by CMR from grade 1 to 2, whereas differences were much smaller for T1ρ (9%, P=0.14), native T1 (5.5%, P=0.12), and perfusion (−21%, P=0.05). ConclusionA non-contrast CMR index based on T1ρ dispersion contrast was shown in preliminary studies to detect and correlate with the extent of myocardial fibrosis identified histopathologically. A non-contrast approach may have important implications for managing cardiac patients with heart failure, particularly in the presence of impaired renal function.

De Novo Discovery of [Hdabco]BF4 Molecular Ferroelectric Thin Film for Nonvolatile Low-Voltage Memories.

To date, the field of ferroelectric random access memories (FeRAMs) is mainly dominated by inorganic ferroelectric thin films like Pb(Zr,Ti)O3, which suffer from the issues of environmental harmfulness, high processing temperatures, and high fabrication costs. In these respects, molecular ferroelectric thin films are particularly advantageous and thus become promising alternatives to the conventional inorganic ones. For the prospect of FeRAMs applications, they should fulfill the requirements of effective polarization switching and low-voltage, high-speed operation. Despite recent advancements, molecular ferroelectric thin films with such high performance still remain a huge blank. Herein we present the first example of a large-area continuous biaxial molecular ferroelectric thin film that gets very close to the goal of application in FeRAMs: [Hdabco]BF4 (dabco = diazabicyclo[2.2.2]octane). In addition to excellent film performance, it is the coexistence of a low coercive voltage of ∼12 V and ultrafast polarization switching at a significantly high frequency of 20 kHz that affords [Hdabco]BF4 considerable potential for memory devices. Particularly, piezoresponse force microscopy (PFM) clearly demonstrates the four polarization directions and polarization switching at a low voltage down to ∼4.2 V (with an ∼150 nm thick film). This innovative work on high-performance molecular ferroelectric thin films, which can be compatible with wearable devices, will inject new vitality to the low-power information field.

Quality of Non-Bronchoscopic Bronchoalveolar Lavage Specimens and the Diagnosis of Ventilator-Associated Pneumonia

BackgroundVentilator-associated pneumonia (VAP) is a significant cause of hospital-acquired infection. Many institutions use National Healthcare Safety Network (NHSN) definitions for VAP surveillance. One criterion of the NHSN definition for possible VAP (PVAP) is a positive culture obtained via non-bronchoscopic bronchoalveolar lavage (NB-BAL). NB-BAL specimens are not routinely assessed for oropharyngeal contamination prior to quantitative culture. Thus, we hypothesized that NB-BALs can yield poor quality specimens that may contribute to the misdiagnosis of PVAP.MethodsFrom May 2016 to January 2017, we performed background quality assessments for NB-BAL specimens collected from patients on mechanical ventilation for >3 days. Thereafter, we retrospectively reviewed NB-BAL quality, culture results, and contribution to NHSN-defined PVAPs. Quality assessments included number of white blood cells (WBC) or squamous epithelial cells (SEC) per low-power field (lpf). Specimens were deemed acceptable if they had ≤10 SEC/lpf by “standard” criteria and zero SEC/lpf by “strict” criteria. All specimens were cultured regardless of quality assessment results, which were not revealed to ordering clinicians.ResultsOf 117 NB-BAL specimens, 8 (7%) did not pass standard quality assessment and an additional 47 (40%) did not pass strict quality assessment. Most samples (82%) were purulent (>25 WBC/lpf). Overall, 56 (48%) of samples resulted in significant growth of at least one species of bacteria (>104 CFU/mL). Of the 8 samples that did not pass standard assessment, 7 (87%) resulted in significant bacterial growth. Four PVAPs were diagnosed on the basis of NB-BAL specimens. Of these, all were acceptable by standard criteria, but one failed by strict criteria.ConclusionApproximately 50% of our NB-BAL specimens had evidence of oropharyngeal contamination on quality assessment, including one specimen that contributed to a NHSN-reported PVAP. While limited by small sample size and short study duration, our data suggest that the quality of NB-BAL specimens may affect the diagnosis and surveillance of VAP.Disclosures All authors: No reported disclosures.

Protective and damaging role of electromagnetic influences on biomembranes

The paper presents the results of studies of the effect of an alternating low-power electromagnetic field and light irradiation with monochromatic light from a laser source on the state of biological membranes. It was shown that the effect of these factors on the erythrocyte membrane causes a different effect andaffects its resistance differently, which is reflected in the change in the erythrogram of acid hemolysis in the experiment. It has been established that the action of an ultrahigh-frequency electromagnetic field leads to a decrease in the resistance of erythrocytes and an increase in the rate of lysis of red cells. Laserirradiation with a low-power helium-neon laser at low exposure increases the resistance of red blood cells to acid hemolysis. Increasing exposure reduces the effect noted. With simultaneous processing of blood samples by UHF (ultra high frequency electromagnetic fields) source and laser light, a significant decreasein the negative effect of the UHF field on the resistance of biomembranes is noted. Possible mechanisms of marked biological effects are discussed.

Room-Temperature Spin Filtering in Metallic Ferromagnet-Multilayer Graphene-Ferromagnet Junctions.

We report room-temperature negative magnetoresistance in ferromagnet-graphene-ferromagnet (FM|Gr|FM) junctions with minority spin polarization exceeding 80%, consistent with predictions of strong minority spin filtering. We fabricated arrays of such junctions via chemical vapor deposition of multilayer graphene on lattice-matched single-crystal NiFe(111) films and standard photolithographic patterning and etching techniques. The junctions exhibit metallic transport behavior, low resistance, and the negative magnetoresistance characteristic of a minority spin filter interface throughout the temperature range 10 to 300 K. We develop a device model to incorporate the predicted spin filtering by explicitly treating a metallic minority spin channel with spin current conversion and a tunnel barrier majority spin channel and extract spin polarization of at least 80% in the graphene layer in our structures. The junctions also show antiferromagnetic coupling, consistent with several recent predictions. The methods and findings are relevant to fast-readout low-power magnetic random access memory technology, spin logic devices, and low-power magnetic field sensors.

A 9 b/12 b 50 MS/s experimental ADC with continuous approximation architecture in 65 nm CMOS

A 9 bits 50 MS/s 0.5 mW continuous approximation mixed successive approximation (CAR&SAR) ADC is presented. A 12 bits 50 MS/s 0.6 mW CAR&CAR ADC is presented. In the field of low power and high performance ADC, CAR is a new architecture different from SAR. It is faster and easier to get high accuracy. Here we will introduce CAR and its circuit implementation, and the 9 bits experimental ADC is designed to verify CARADC's feasibility. Meanwhile, its resolution can be extended to 12 bits with adding an extra CAR, and then the performance is raised to 0.6 mW 50 MS/s 72 dB SNDR at TT corner and the Walden FOM is 3.6 fj/conv-step. The 9 b ADC was fabricated by using TSMC 1P9M 65 nm CMOS technology. The ADC achieves 50 dB SNDR and the realized Walden FOM is 34 fj/conv-step. The simulation and measurement results prove that CAR is available in the low power and high performance ADC and it even outperforms SAR. The ADC core occupies an active area of 0.045 mm2.