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1.
Clin Nutr ; 43(5): 1073-1078, 2024 May.
Article in English | MEDLINE | ID: mdl-38579369

ABSTRACT

BACKGROUND & AIM: In hospitalized patients, daily protein intake remains far below WHO requirements for healthy adults (0.8 g·kg-1·d-1) as well as ESPEN guidelines for patients (1.2-1.5 g·kg-1·d-1). Providing access to a pre-sleep protein dense snack between dinner and going to bed may serve as a great opportunity to increase daily energy and protein intake in hospitalized patients. However, it remains to be assessed whether protein provision prior to sleep effectively increases protein intake, or may reduce food intake throughout the remainder of the day(s). The present study evaluated the impact of giving access to a pre-sleep snack on daily energy and protein intake in patients throughout their hospitalization. METHODS: Patients admitted to the surgical wards of the Maastricht University Medical Centre+ were randomly allocated to usual care (n = 51) or given access to a pre-sleep snack (n = 50). The pre-sleep snack consisted of 103 g cheese cubes (30 g protein) provided between 7:30 and 9:30 PM, prior to sleep. All food provided and all food consumed was weighed and recorded throughout (2-7 days) hospitalization. Daily energy and protein intake and distribution were calculated. Data were analyzed by independent T-Tests with P < 0.05 considered as statistically significant. RESULTS: Daily energy intake was higher in the pre-sleep group (1353 ± 424 kcal d-1) when compared to the usual care group (1190 ± 402 kcal·d-1; P = 0.049). Providing patients access to a pre-sleep snack resulted in a 17% (11 ± 9 g) higher daily protein intake (0.81 ± 0.29 g·kg-1·d-1) when compared to the usual care group (0.69 ± 0.28 g·kg-1·d-1; P = 0.045). Protein intake at breakfast, lunch, and dinner did not differ between the pre-sleep and usual care groups (all P > 0.05). CONCLUSION: Providing access to a pre-sleep protein snack, in the form of protein dense food items such as cheese, represents an effective dietary strategy to increase daily energy and protein intake in hospitalized patients. Patients consuming pre-sleep protein snacks do not compensate by lowering energy or protein intake throughout the remainder of the days. Pre-sleep protein dense food provision should be implemented in hospital food logistics to improve the nutritional intake of patients. TRIAL REGISTER NO: NL8507 (https://trialsearch.who.int/).


Subject(s)
Dietary Proteins , Energy Intake , Hospitalization , Sleep , Snacks , Humans , Male , Female , Dietary Proteins/administration & dosage , Middle Aged , Aged , Sleep/physiology , Adult
2.
BMJ Mil Health ; 2024 Feb 06.
Article in English | MEDLINE | ID: mdl-38124226

ABSTRACT

INTRODUCTION: Canadian Armed Forces (CAF) members must complete an annual fitness evaluation. Members with a total hip arthroplasty (THA) may be at risk of injury during these strenuous tests. To inform CAF policy, we sought expert consensus on the safety of fitness testing for members with a THA. METHODS: We conducted a three-round Delphi study with a panel of hip arthroplasty experts to determine the safety of CAF operational fitness evaluations for members with a THA. The experts evaluated videos of the 10 individual tasks included in the evaluations. RESULTS: All individual tasks were judged to be safe by consensus. One task, which involves digging with a shovel, was considered safe provided that participants avoid deep hip flexion. The nine other tasks were judged to be safe without modifications or interventions. The experts also supported a policy recommendation that would allow members to perform military fitness evaluations if they (1) have a primary THA, (2) had no episodes of instability, (3) are at least 12 months postoperatively and (4) have been cleared by an orthopaedic surgeon and a physiatrist/physiotherapist. CONCLUSION: A panel of arthroplasty experts concluded, based on video analysis, that CAF fitness evaluations are generally safe for members with a THA.

3.
Front Microbiol ; 14: 1231832, 2023.
Article in English | MEDLINE | ID: mdl-37680529

ABSTRACT

Grapevine trunk diseases (GTDs) are a substantial challenge to viticulture, especially with a lack of available control measures. The lack of approved fungicides necessitates the exploration of alternative controls. One promising approach is the investigation of disease escape plants, which remain healthy under high disease pressure, likely due to their microbiome function. This study explored the microbiome of grapevines with the disease escape phenotype. DNA metabarcoding of the ribosomal internal transcribed spacer 1 (ITS1) and 16S ribosomal RNA gene was applied to trunk tissues of GTD escape and adjacent diseased vines. Our findings showed that the GTD escape vines had a significantly different microbiome compared with diseased vines. The GTD escape vines consistently harbored a higher relative abundance of the bacterial taxa Pseudomonas and Hymenobacter. Among fungi, Aureobasidium and Rhodotorula were differentially associated with GTD escape vines, while the GTD pathogen, Eutypa, was associated with the diseased vines. This is the first report of the link between the GTD escape phenotype and the grapevine microbiome.

4.
Rev Med Interne ; 44(11): 594-601, 2023 Nov.
Article in French | MEDLINE | ID: mdl-37438189

ABSTRACT

Since the discovery of DNA as the support of genetic information, the challenge for generations of life scientists was to understand the mechanisms underlying the process that translate the sequence of a gene to a phenotype. In the 1950s, the concept of epigenetics was defined by the British biologist Conrad H. Waddington as the study of "epigenesis" that governs the biological processes involved in the development of any organism. The term epigenetics, now best defined as "above the DNA sequence" reflects the gene-environment interactions by which genes determine traits. Since, its first description, studies underlying the mechanisms involved in these processes has led to an increasing understanding of the regulation all genome transactions such as transcription, replication, repair and the biological pathways coordinated by these mechanisms. We will discuss here the main principles regulating epigenetic processes, their roles in physiology, their evolution over the life time and their implications in medicine.


Subject(s)
DNA Methylation , Histones , Humans , Histones/genetics , Histones/metabolism , Epigenesis, Genetic , Phenotype , Gene-Environment Interaction
5.
Clin Nutr ; 42(8): 1436-1444, 2023 08.
Article in English | MEDLINE | ID: mdl-37441814

ABSTRACT

BACKGROUND & AIMS: Hemodialysis removes amino acids from the circulation, thereby stimulating muscle proteolysis. Protein ingestion during hemodialysis can compensate for amino acid removal but may also increase uremic toxin production. Branched-chain ketoacid (BCKA) co-ingestion may provide an additional anabolic stimulus without adding to uremic toxin accumulation. In the present study we assessed the impact of BCKA co-ingestion with protein on forearm amino acid balance and amino acid oxidation during hemodialysis. METHODS: Nine patients (age: 73 ± 10 y) on chronic hemodialysis participated in this crossover trial. During two 4-h hemodialysis sessions, patients ingested 18 g protein with (PRO + BCKA) or without (PRO) 9 g BCKAs in a randomized order. Test beverages were labeled with L-[ring-13C6]-phenylalanine and provided throughout the last 3 h of hemodialysis as 18 equal sips consumed with 10-min intervals. Arterial and venous plasma as well as breath samples were collected frequently throughout hemodialysis. RESULTS: Arterial plasma total amino acid (TAA) concentrations during PRO and PRO + BCKA treatments were significantly lower after 1 h of hemodialysis (2.6 ± 0.3 and 2.6 ± 0.3 mmol/L, respectively) when compared to pre-hemodialysis concentrations (4.2 ± 1.0 and 4.0 ± 0.5 mmol/L, respectively; time effect: P < 0.001). Arterial plasma TAA concentrations increased throughout test beverage ingestion (time effect: P = 0.027) without differences between treatments (time∗treatment: P = 0.62). Forearm arteriovenous TAA balance during test beverage ingestion did not differ between timepoints (time effect: P = 0.31) or treatments (time∗treatment: P = 0.34). Whole-body phenylalanine oxidation was 33 ± 16% lower during PRO + BCKA when compared to PRO treatments (P < 0.001). CONCLUSIONS: BCKA co-ingestion with protein during hemodialysis does not improve forearm net protein balance but lowers amino acid oxidation.


Subject(s)
Amino Acids , Uremic Toxins , Humans , Middle Aged , Aged , Aged, 80 and over , Cross-Over Studies , Proteins/metabolism , Keto Acids , Phenylalanine/metabolism , Renal Dialysis , Eating , Muscle, Skeletal/metabolism
6.
J Pharm Health Serv Res ; 13(3): 168-171, 2022 Sep.
Article in English | MEDLINE | ID: mdl-36247367

ABSTRACT

Objective: One in four persons living with HIV in the USA is a woman. While the annual HIV diagnoses for 2019 decreased by approximately 9% when compared with 2015, this decrease was seen in men, while the rates remained stable for women. Pre-exposure prophylaxis (PrEP) is one major biomedical tool that could benefit women at risk of HIV. However, women only account for approximately 5% of PrEP users annually. The objective of this study is to identify and address the gender disparity in PrEP use. Methods: This study used epidemiological data from the AIDSVu database to confirm the presence of a gender disparity in PrEP use across the USA. Cross-sectional data from 2019 showed that PrEP use was significantly higher in men, which suggested the existence of a disparity. The PrEP-to-Need ratio was then used to examine the trends in PrEP use relative to the rate of HIV infections, from 2012 to 2019, and to confirm the existence of the gender disparity in PrEP use. Key findings: There is a marked gender disparity in PrEP use. This disparity is widening and therefore demands more attention to women at risk of HIV. Some recommendations for addressing the disparity include the following: raising awareness, capacity building for providers, scaling up efforts to better reach women at risk of HIV and additional research to understand the drivers of the disparity. Conclusions: Policy makers could therefore prioritize the health outcomes of women by promoting research and education aimed at extending PrEP offerings to effectively reach women.

7.
BMC Microbiol ; 22(1): 126, 2022 05 10.
Article in English | MEDLINE | ID: mdl-35538413

ABSTRACT

Grapevine trunk diseases (GTDs) are a threat to grape production worldwide, with a diverse collection of fungal species implicated in disease onset. Due to the long-term and complex nature of GTDs, simultaneous detection of multiple microbial species can enhance understanding of disease development. We used DNA metabarcoding of ribosomal internal transcribed spacer 1 (ITS1) sequences, supported by specific PCR and microbial isolation, to establish the presence of trunk pathogens across 11 vineyards (11-26 years old) over three years in Marlborough, the largest wine producing region in New Zealand. Using a reference database of trunk pathogen sequences, species previously associated with GTD, such as Cadophora luteo-olivacea, Diplodia seriata, Diplodia mutila, Neofusicoccum australe, and Seimatosporium vitis, were identified as highly represented across the vineyard region. The well-known pathogens Phaeomoniella chlamydospora and Eutypa lata had especially high relative abundance across the dataset, with P. chlamydospora reads present between 22 and 84% (average 52%) across the vineyards. Screening of sequences against broader, publicly available databases revealed further fungal species within families and orders known to contain pathogens, many of which appeared to be endemic to New Zealand. The presence of several wood-rotting basidiomycetes (mostly Hymenochaetales) was detected for the first time in the Marlborough vineyard region, notably, the native Inonotus nothofagii which was present at 1-2% relative abundance in two vineyards.


Subject(s)
Plant Diseases , Vitis , Adolescent , Adult , Child , DNA Barcoding, Taxonomic , Farms , Humans , New Zealand , Plant Diseases/microbiology , Vitis/microbiology , Young Adult
8.
J Mech Behav Biomed Mater ; 110: 103944, 2020 10.
Article in English | MEDLINE | ID: mdl-32957237

ABSTRACT

BACKGROUND: During revision total knee arthroplasty (rTKA), proximal tibial bone loss is frequently encountered and can result in a less-stable bone-implant fixation. A 3D printed titanium revision augment that conforms to the irregular shape of the proximal tibia was recently developed. The purpose of this study was to evaluate the fixation stability of rTKA with this augment in comparison to conventional cemented rTKA. METHODS: Primary total knee arthroplasty (pTKA) surgery was performed on 11 pairs of thawed fresh-frozen cadaveric tibias (22 tibias). Fixation stability testing was conducted using a three-stage eccentric loading protocol. Bone-implant micromotion was measured using a high-resolution optical system. The pTKA were removed. Revision TKA was performed using a 3D printed titanium augment or a standard fully cemented stem. The three-stage eccentric loading protocol was repeated and micromotion was measured for the revision implants. RESULTS: After rTKA, the mean vertical micromotion was 28.1 µm ± (SD) 20.3 µm in the control group and 17.5 µm ± 18.7 µm in the experimental group. There was significantly less micromotion in the experimental group (p = 0.029). CONCLUSIONS: This study suggests that early fixation stability of revision TKA with the novel 3D printed titanium augment is better then the conventional fully cemented rTKA. The early press-fit fixation of the augment is likely sufficient for promoting bony ingrowth of the augment in vivo. Further studies are needed to investigate the long-term in-vivo fixation of the novel 3D printed augment.


Subject(s)
Arthroplasty, Replacement, Knee , Knee Prosthesis , Cadaver , Humans , Printing, Three-Dimensional , Prosthesis Design , Tibia/surgery , Titanium
9.
BMC Pulm Med ; 19(1): 217, 2019 Nov 19.
Article in English | MEDLINE | ID: mdl-31744499

ABSTRACT

BACKGROUND: Decades of clinical research into pulsed oxygen delivery has shown variable efficacy between users, and across a user's behaviours (sleep, rest, activity). Modern portable oxygen concentrators (POCs) have been shown as effective as other oxygen delivery devices in many circumstances. However, there are concerns that they are not effective during sleep when the breathing is shallow, and at very high respiratory rates as during physical exertion. It can be challenging to examine the determinants of POC efficacy clinically due to the heterogeneity of lung function within oxygen users, the diversity of user behaviour, and measurement issues. Representative bench testing may help identify key determinants of pulsed-oxygen device efficacy. METHODS: Three contemporary devices were bench-evaluated across three simulated breathing behaviours: activity, rest, & oronasal breathing during sleep. Emphasis was placed on breathing patterns representative of oxygen users. RESULTS: All three POCs performed well during simulated breathing during exertion and at rest. Differences in triggering ability were noted for the scenario of oronasal breathing during sleep. CONCLUSIONS: The results are supportive of contemporary POC triggering abilities. The differences shown in ultimate trigger sensitivity may have relevance to oronasal breathing during sleep or other challenging scenarios for pulsed oxygen delivery, such as dominant mouth breathing during exertion or unfavourable nasal geometry.


Subject(s)
Oxygen Inhalation Therapy/instrumentation , Oxygen/administration & dosage , Adult , Cannula , Computer Simulation , Humans , Lung/physiopathology , Models, Anatomic , Oximetry , Pulmonary Disease, Chronic Obstructive/physiopathology , Pulmonary Disease, Chronic Obstructive/therapy , Pulmonary Ventilation , Respiratory Physiological Phenomena , Sleep
10.
Plant Dis ; 103(3): 519-525, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30632468

ABSTRACT

The grapevine trunk diseases Eutypa and Botryosphaeria dieback threaten the sustainability of vineyards worldwide. This study aimed to develop practical and efficient wound protection strategies, which will lead to widespread adoption of preventative control for these diseases and increased longevity of vineyards. Five fungicides (tebuconazole, carbendazim, fluazinam, mancozeb, and flusilazole) were evaluated for efficacy against Eutypa lata and Neofusicoccum luteum infection on pruning wounds of 'Sauvignon blanc' in a New Zealand vineyard. All five fungicides controlled infection by both pathogens to varying degrees, with mean percent disease control of 70 to 90% for E. lata and 33 to 93% for N. luteum. This has led to the first known registration of a fungicide, fluazinam (Gem), for simultaneous control of both Eutypa and Botryosphaeria dieback. Furthermore, application of carbendazim with tractor-driven sprayers provided similar control of E. lata and N. luteum to that when applied by hand with a paintbrush. This constitutes the first report of Botryosphaeria dieback control with fungicides applied with tractor-driven sprayers.


Subject(s)
Ascomycota , Fungicides, Industrial , Vitis , Ascomycota/drug effects , Ascomycota/physiology , Fungicides, Industrial/pharmacology , New Zealand , Plant Diseases/prevention & control , Vitis/microbiology
11.
J Affect Disord ; 225: 129-136, 2018 01 01.
Article in English | MEDLINE | ID: mdl-28826089

ABSTRACT

BACKGROUND: Sex differences in emotion processing may play a role in women's increased risk for Major Depressive Disorder (MDD). However, studies of sex differences in brain mechanisms involved in emotion processing in MDD (or interactions of sex and diagnosis) are sparse. METHODS: We conducted an event-related fMRI study examining the interactive and distinct effects of sex and MDD on neural activity during a facial emotion perception task. To minimize effects of current affective state and cumulative disease burden, we studied participants with remitted MDD (rMDD) who were early in the course of the illness. In total, 88 individuals aged 18-23 participated, including 48 with rMDD (32 female) and 40 healthy controls (HC; 25 female). RESULTS: fMRI revealed an interaction between sex and diagnosis for sad and neutral facial expressions in the superior frontal gyrus and left middle temporal gyrus. Results also revealed an interaction of sex with diagnosis in the amygdala. LIMITATIONS: Data was from two sites, which might increase variability, but it also increases power to examine sex by diagnosis interactions. CONCLUSIONS: This study demonstrates the importance of taking sex differences into account when examining potential trait (or scar) mechanisms that could be useful in identifying individuals at-risk for MDD as well as for evaluating potential therapeutic innovations.


Subject(s)
Amygdala/pathology , Depression/pathology , Facial Expression , Prefrontal Cortex/pathology , Depression/psychology , Emotions , Face , Female , Humans , Magnetic Resonance Imaging , Male , Sex Characteristics , Young Adult
12.
BMC Pulm Med ; 17(1): 85, 2017 May 23.
Article in English | MEDLINE | ID: mdl-28535820

ABSTRACT

BACKGROUND: The lung-protective ventilation bundle has been shown to reduce mortality in adult acute respiratory distress syndrome (ARDS). This concept has expanded to other areas of acute adult ventilation and is recommended for pediatric ventilation. A component of lung-protective ventilation relies on a prediction of lean body weight from height. The predicted body weight (PBW) relationship employed in the ARDS Network trial is considered valid only for adults, with a dedicated formula required for each sex. No agreed PBW formula applies to smaller body sizes. This analysis investigated whether it might be practical to derive a unisex PBW formula spanning all body sizes, while retaining relevance to established adult protective ventilation practice. METHODS: Historic population-based growth charts were adopted as a reference for lean body weight, from pre-term infant through to adult median weight. The traditional ARDSNet PBW formulae acted as the reference for prevailing protective ventilation practice. Error limits for derived PBW models were relative to these references. RESULTS: The ARDSNet PBW formulae typically predict weights heavier than the population median, therefore no single relationship could satisfy both references. Four alternate piecewise-linear lean body-weight predictive formulae were presented for consideration, each with different balance between the objectives. CONCLUSIONS: The 'PBWuf + MBW' model is proposed as an appropriate compromise between prevailing practice and simplification, while also better representing lean adult body-weight. This model applies the ARDSNet 'female' formula to both adult sexes, while providing a tight fit to median body weight at smaller statures down to pre-term. The 'PBWmf + MBW' model retains consistency with current practice over the adult range, while adding prediction for small statures.


Subject(s)
Body Weight , Models, Biological , Respiration, Artificial , Adolescent , Adult , Body Height , Child , Child, Preschool , Female , Growth Charts , Humans , Infant , Infant, Newborn , Infant, Premature , Male , Mathematical Concepts , Reference Values , Young Adult
13.
Neurogastroenterol Motil ; 28(1): 85-90, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26510823

ABSTRACT

BACKGROUND: Oropharyngeal dysphagia is prevalent in individuals with amyotrophic lateral sclerosis (ALS) leading to malnutrition, aspiration pneumonia, and death. These factors necessitate early detection of at-risk patients to prolong maintenance of safe oral intake and pulmonary function. This study aimed to evaluate the discriminant ability of the Eating Assessment Tool (EAT-10) to identify ALS patients with unsafe airway protection during swallowing. METHODS: Seventy ALS patients completed the EAT-10 survey and underwent a standardized videofluoroscopic evaluation of swallowing. Two blinded raters determined airway safety using the Penetration Aspiration Scale (PAS). A between groups anova (safe vs penetrators vs aspirators) was conducted and sensitivity, specificity, area under the curve (AUC), and likelihood ratios calculated. KEY RESULTS: Mean EAT-10 scores for safe swallowers, penetrators, and aspirators (SEM) were: 4.28 (0.79) vs 7.10 (1.79) vs 20.50 (3.19), respectively, with significant differences noted for aspirators vs safe swallowers and aspirators vs penetrators (p < 0.001). The EAT-10 demonstrated good discriminant ability to accurately identify ALS penetrator/aspirators (PAS ≥3) with a cut off score of 3 (AUC: 0.77, sensitivity: 88%, specificity: 57%). The EAT-10 demonstrated excellent accuracy at identifying aspirators (PAS ≥6) utilizing a cut off score of 8 (AUC: 0.88, sensitivity: 86%, specificity: 72%, likelihood ratio: 3.1, negative predictive value: 95.5%). CONCLUSIONS & INFERENCES: The EAT-10 differentiated safe vs unsafe swallowing in ALS patients. This patient self-report scale could represent a quick and meaningful aide to dysphagia screening in busy ALS clinics for the identification and referral of dysphagic patients for further instrumental evaluation.


Subject(s)
Amyotrophic Lateral Sclerosis/diagnosis , Deglutition Disorders/diagnosis , Respiratory Aspiration/diagnosis , Adult , Aged , Aged, 80 and over , Amyotrophic Lateral Sclerosis/complications , Area Under Curve , Barium Sulfate , Contrast Media , Deglutition Disorders/etiology , Female , Fluoroscopy , Humans , Male , Middle Aged , Respiratory Aspiration/etiology , Sensitivity and Specificity , Surveys and Questionnaires , Video Recording
14.
J Chem Phys ; 143(20): 204308, 2015 Nov 28.
Article in English | MEDLINE | ID: mdl-26627960

ABSTRACT

We present models for a heteronuclear diatomic molecular ion in a linear Paul trap in a rigid-rotor approximation, one purely classical and the other where the center-of-mass motion is treated classically, while rotational motion is quantized. We study the rotational dynamics and their influence on the motion of the center-of-mass, in the presence of the coupling between the permanent dipole moment of the ion and the trapping electric field. We show that the presence of the permanent dipole moment affects the trajectory of the ion and that it departs from the Mathieu equation solution found for atomic ions. For the case of quantum rotations, we also evidence the effect of the above-mentioned coupling on the rotational states of the ion.

15.
Phys Rev Lett ; 113(21): 217206, 2014 Nov 21.
Article in English | MEDLINE | ID: mdl-25479521

ABSTRACT

We obtain a fundamental instability of the magnetization-switching fronts in superparamagnetic and ferromagnetic materials such as crystals of nanomagnets, ferromagnetic nanowires, and systems of quantum dots with large spin. We develop the instability theory for both linear and nonlinear stages. By using numerical simulations we investigate the instability properties focusing on spin avalanches in crystals of nanomagnets. The instability distorts spontaneously the fronts and leads to a complex multidimensional front dynamics. We show that the instability has a universal physical nature, with a deep relationship to a wide variety of physical systems, such as the Darrieus-Landau instability of deflagration fronts in combustion, inertial confinement fusion, and thermonuclear supernovae, and the instability of doping fronts in organic semiconductors.

16.
Toxicol Lett ; 214(2): 109-19, 2012 Oct 17.
Article in English | MEDLINE | ID: mdl-22944471

ABSTRACT

Nano-aerosols composed of large agglomerates (LA) (>100nm) are more likely to promote pulmonary clearance via macrophages phagocytosis. Small agglomerates (SA) (<100nm) seem to escape this first defense mechanism and are more likely to interact directly with biological material. These different mechanisms can influence pulmonary toxicity. This hypothesis was evaluated by comparing the relative pulmonary toxicity induced by aerosolized nano-TiO(2) showing two different agglomeration states: SA (<100nm) and LA (>100nm) at mass concentrations of 2 or 7mg/m(3). Groups of Fisher 344 male rats were nose-only exposed for 6h. The median number aerodynamic diameters were 30 and 185nm at 2mg/m(3), and 31 and 194nm at 7mg/m(3). We found in rat's bronchoalveolar lavage fluids (BALF) a significant 2.1-fold increase in the number of neutrophils (p<0.05) in the group exposed to the 7mg/m(3) LA nano-aerosol suggesting a mild inflammatory response. Rats exposed to the 7mg/m(3) SA nano-aerosol showed a 1.8-fold increase in LDH activity and 8-isoprostane concentration in BALF, providing evidence for cytotoxic and oxidative stress effects. Our results indicate that biological responses to nanoparticles (NP) might depend on the dimension and concentration of NP agglomerates.


Subject(s)
Lung/drug effects , Nanoparticles/toxicity , Titanium/toxicity , Administration, Inhalation , Aerosols/toxicity , Animals , Bronchoalveolar Lavage Fluid/cytology , Cytokines/metabolism , Lung/immunology , Lung/pathology , Male , Microscopy, Electron, Transmission , Nanoparticles/ultrastructure , Particle Size , Rats , Rats, Inbred F344 , Titanium/administration & dosage , X-Ray Diffraction
17.
Opt Express ; 19(24): 23664-70, 2011 Nov 21.
Article in English | MEDLINE | ID: mdl-22109392

ABSTRACT

Natural lithography with 100-nm-diameter SiO(2) spheres followed by inductively coupled plasma etching was used to texture the surface of 4H-SiC for a wide-spectrum large-acceptance-angle anti-reflective layer. The surface showed low normal-incidence reflectance of < 5% over a wide spectrum from 250 nm to 550 nm. Photodiodes fabricated from the surface-textured SiC showed broader spectral and angular responsivity than SiC photodiodes with SiO(2) antireflective coating. The textured SiC photodiodes showed peak responsivity of 116 mA/W, large angle of acceptance angle (< 2% decrease in responsivity at 50° incident angle) and low dark current at 10V.


Subject(s)
Carbon Compounds, Inorganic/chemistry , Nanospheres/chemistry , Nanotechnology/instrumentation , Photometry/instrumentation , Semiconductors , Silicon Compounds/chemistry , Equipment Design , Equipment Failure Analysis , Light , Photography/methods , Scattering, Radiation
18.
Phys Rev E Stat Nonlin Soft Matter Phys ; 83(2 Pt 1): 020101, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21405799

ABSTRACT

We have realized real-time steering of the directed transport in a Brownian motor based on cold atoms in optical lattices and demonstrate drifts along predesigned paths. The transport is induced by spatiotemporal asymmetries in the system, where we can control the spatial part, and we show that the response to changes in asymmetry is very fast. In addition to directional steering, a real-time control of the magnitude of the average drift velocity and an on-off switching of the motor are also demonstrated. We use a noninvasive real-time detection of the transport, enabling feedback control of the system.

19.
Phys Rev E Stat Nonlin Soft Matter Phys ; 83(2 Pt 1): 020102, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21405800

ABSTRACT

The rectification of noise into directed movement or useful energy is utilized by many different systems. The peculiar nature of the energy source and conceptual differences between such Brownian motor systems makes a characterization of the performance far from straightforward. In this work, where the Brownian motor consists of atoms interacting with dissipative optical lattices, we adopt existing theory and present experimental measurements for both the efficiency and the transport coherence. We achieve up to 0.3% for the efficiency and 0.01 for the Péclet number.

20.
Rev Sci Instrum ; 82(2): 023706, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21361600

ABSTRACT

In this work we demonstrate the use of two-dimensional detectors to improve the signal-to-noise ratio (SNR) and sensitivity in spectral-domain phase microscopy for subnanometer accuracy measurements. We show that an increase in SNR can be obtained, from 82 dB to 105 dB, using 150 pixel lines of a low-cost CCD camera as compared to a single line, to compute an averaged axial scan. In optimal mechanical conditions, phase stability as small as 92 µrad, corresponding to 6 pm displacement accuracy, could be obtained. We also experimentally demonstrate the benefit of spatial-averaging in terms of the reduction of signal fading due to an axially moving sample. The applications of the improved system are illustrated by imaging live cells in culture.


Subject(s)
Microscopy/instrumentation , Cell Membrane/metabolism , HeLa Cells , Humans
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