Near-infrared Spectrophotometry Research Articles

Study of polar desert carbon yields many questions

Study of polar desert carbon yields many questions

Investigation on Optimally Performing Sensor Substrates through Bio-fouling of Immunoglobulin-Conjugated Gold Nanoparticles

Biosensing technology represents a superior way of identifying a wide range of biomolecules that exist in the human body, food, water, and other environmental sources. In this regard, human health issues are a growing global concern, and the development of effective methods for the detection and differentiation of biomolecules during diagnosis and/or treatment of diseases is essential. However, achieving adequate levels of sensitivity and specificity will be fundamental for the successful clinical application of biosensing technology. Notably, sensitivity and specificity are highly dependent on non-fouling (specificity) of biomolecules on the sensing surfaces, particularly with regard to nanoparticle-tagged biomolecules. Here, the authors have evaluated bio-fouling (i.e., biological non-specificity) by analysing four distinct sensing substrates (gold, silicon, silica and platinum) using anti-mouse immunoglobulin-conjugated gold nanoparticles. As evidenced by scanning electron microscopy and ultraviolet–visible–near-infrared recording spectrophotometry, silica (SiO2) lacked bio-fouling, whereas gold (Au) showed high bio-fouling potential. Indeed, Raman spectroscopic analysis further confirmed these results. Thus, the present findings indicate that SiO2 is an optimal substrate for biosensor development.

Which are the duties and the limits of nursing in neonatal ventilation?

It's difficult to talk about nurse's autonomy in ventilation assistance, because is a medical prescription. However in accordance with the Code of ethics, the professional profile and law 42/99, nurses have decision and operative autonomy in nursing care, which is achieved through specific autonomous and complementary interventions of intellectual, technical-scientific, managerial, relational and educational nature [1-3]. The treatment of respiratory meets the need: help optimize gas exchange, reduce breathing exertion and promote healing process reducing hemodynamic interferences. These goals can be reached individualizing the treatment according to the pathophysiological features of the disease and the time evolution of single pathology. Monitoring peripheral oxygen saturation is more suitable method in the ventilated preterm (<27 weeks) because transcutaneous oxygenation monitoring is not of routine use for lack of an adequate correlation with the blood gas and for highly sensitive skin. Many studies suggest the prevention of lung damage and retinopathy of preterm concerning a prolonged hyperoxia by setting alarm limits in the event of administration of an oxygen concentration higher than 21%. Numerous clinical conditions, including the need for mechanical ventilation, can affect and change the brain oxygenation. The near-infrared ray spectrophotometry (NIRS) is a technique that allows non-invasive monitoring of oxygenation and cerebral hemodynamics. It provides a single quantitative parameter rSO2 (regional saturation of oxygen) as an index of tissue oxygenation [4]. Compared to the intubated newborn there is not a unique method and standardized anchorage of the endotracheal tube. The quality of the attachment can vary greatly depending on the choice of the tape and according to the method of taping adopted. No recommendation exists in the literature about the method of taping: the most widely used systems include the use of one or two strips cut to Y or H. The adhesive tape, indisputably considered the system capable of guaranteeing the best results in terms of sealing, when applied with a taping system and encoded together with a hydrocolloid protective largely reduces the risk of injury[5-8]. The aspiration of the airways in infants should be based on careful clinical assessment and not on a routine basis. It recommended to avoid suctioning the nose but use saline drops instead, then suction the oropharynx [9]. Care posture is crucial because it promotes the stabilization of the neonatal functions and prevents bad posture [10]. It is recommended the use of ventilation systems with manual pressure control and delivered volumes in order to safeguard the delicate lung tissue.

The Effect of Decreasing Flow Rate on Cerebral Hemodynamics During Veno-Arterial Extracorporeal Membrane Oxygenation in Piglets.

To explore the influence of decreasing flow rate on cerebral hemodynamics during veno-arterial extracorporeal membrane oxygenation (va-ECMO), six normoxemic and six hypoxemic piglets were put on va-ECMO. The ECMO flow rate was decreased from the maximal achievable level to 50 mL min1 with steps of 50 mL min1 every 2 minutes. Changes in mean arterial blood pressure (MABP), left common carotid artery blood flow (Qcar), and other physiologic variables were continuously measured. Changes in concentrations of oxyhemoglobin and deoxyhemoglobin were measured using near infrared spectrophotometry (NIRS). Changes in difference between cerebral oxygen hemoglobin and deoxyhemoglobin concentration (ΔcHbD) and total hemoglobin concentration (ΔctHb) were calculated. ΔcHbD represents changes in cerebral blood flow (CBF), and ΔctHb reflects changes in cerebral blood volume (CBV). Data analysis was performed using mixed models and demonstrated a significant positive correlation between ECMO flow and, respectively, MABP (r = 0.7, p < 0.001), Qcar (r = 0.7, p < 0.001), cHbD (r = 0.8, p < 0.001), and ctHb (r = 0.7, p < 0.001). There was no significant relation between oxygenation state preceding ECMO and Qcar, cHbD, and ctHb during decreasing ECMO flow rate. We conclude that decreasing ECMO flow rate ultimately leads to concurrent decrease in MABP, CBF, and CBV.

Utility of near infrared light to determine tissue oxygenation during hepato-biliary surgery.

Near-infrared spectrophotometry assesses cerebral oxygen saturation (ScO2) based on the absorption spectra of oxygenated and deoxygenated hemoglobin, and the translucency of biological tissue, in the near-infrared band. There is increasing evidence that optimising cerebral oxygenation, guided by ScO2, is associated with improved outcomes in a variety of high risk surgical settings. However, in patients with liver disease, bilirubin can potentially render cerebral oximetry inaccurate. As a result, measurement of cerebral oxygen saturation is rarely undertaken in patients undergoing hepatobiliary surgery. We prospectively measured baseline and intraoperative cerebral oxygen saturation in patients undergoing major pancreatic surgery. Indices including bilirubin, sodium, platelets and maximum amplitude on thromboelastography were associated with low baseline ScO2. However, those patients with low ScO2 (≤51%) maintained a similar trend in cerebral oximetry values both at induction and intraoperatively to those with a normal ScO2. We conclude that the pattern of cerebral oximetry is similar in patients undergoing major pancreatic surgery regardless of their underlying liver dysfunction. Therefore, cerebral oximetry may have a role in monitoring neurological function in this high risk group of patients.

Abdominal oxygen saturation for monitoring return of spontaneous circulation in out-of-hospital cardiac arrest using near infrared spectrophometry

AimWe used near-infrared spectrophotometry to assess the initial and final abdominal and cerebral saturations during cardiopulmonary resuscitation (CPR) of patients with out-of-hospital cardiac arrest to determine if there is a correlation between increase in these saturation values and return of spontaneous circulation. Materials and methodsWe evaluated 34 patients with out-of-hospital cardiac arrest without witnesses brought to our emergency department. Abdominal and cerebral saturations were measured using near-infrared spectrophotometry from the start of CPR. Cardiopulmonary resuscitation was performed for a maximum of 30 minutes. The effect of abdominal saturations in patients with or without spontaneous circulation restored through CPR was then assessed. ResultsThirty-four patients (17 males + females) with a mean age of 63.06 ± 11.66 years were included in the study. A significant correlation was determined between increase in abdominal saturations measured at the start and end of CPR and the return of spontaneous circulation (P < .001). A good positive correlation was also identified between abdominal saturation and return of spontaneous circulation. ConclusionPatients with increased abdominal and cerebral saturation values have a higher survival rate after appropriate CPR. This noninvasive measurement system and monitoring of patients during CPR may be a good method of predicting return of spontaneous circulation and assessing abdominal perfusion.

Cyclosiloxane-based liquid-crystalline elastomers containing fluorinated mesogens and chiral crosslinking groups

A series of chiral fluorinated liquid-crystalline elastomers (LCEs) IP-VIP are prepared by 4-cyano-3-fluorophenyl 4′-(undec-10-enoyloxy)biphenyl-4-carboxylate, isosorbide bis(4-allyloxybenzoate) and 2,4,6,8-tetramethylcyclotetrasiloxane via Pt-catalyzed hydrosilylation. The chiral crosslinking moieties increase from IP to IVP. The elastomers IP, IIP, and IIIP containing low content of chiral crosslinking moieties display SC * liquid-crystalline phase, but IVP, VP, and VIP do not show SC * phase except for N* mesophase. The mesophase is testified according to typical diffractogram measured by X-ray diffraction (XRD) analysis. The layer spacings of the LCEs decrease from IP (d-spacing of 34.2 A) to VIP (d-spacing of 31.6 A) with increase of chiral crosslinking groups in the polymers systems. Moreover, the optical properties are performed by ultraviolet–visible–near-infrared spectrophotometry. VP and VIP containing the most chiral crosslinking moieties display maximum reflection in near infrared spectra in the measurement of optical properties, while IP, IIP, IIIP, and IVP do not show obvious maximum reflection. It is interesting that a specific reflection of circularly polarized light appears along with a changing mesophase due to high enough concentration of chiral crosslinking dopants for VP and VIP. All these results suggest that the chiral crosslinking moieties exert influence on the structures of these kinds of LCEs.

Near infrared spectrophotometry (cerebral oximetry) in predicting the return of spontaneous circulation in out-of-hospital cardiac arrest

AimWe assessed out-of-hospital cardiac arrest patients’ cerebral oxygenation during cardiopulmonary resuscitation (CPR) using near infrared spectrophotometry (NIRS). We evaluated the relation between a rise in patients’ cerebral saturation values between the start and end of CPR and return of spontaneous circulation. Materials and methodsTwenty-three patients with unwitnessed out-of-hospital cardiac arrest and brought to our emergency department by emergency ambulance were evaluated. Cerebral saturations from time of start of CPR were measured using NIRS. CPR was performed for a maximum of 30 min. The relation between cerebral saturations in patients with or without return of spontaneous circulation was then evaluated. ResultsTwenty-three patients, 12 (52.2%) female and 11 (47.8%) male, with a mean age of 64.09 ± 13.66 were included. A correlation was determined between a rise in cerebral saturation measured throughout CPR and the return of spontaneous circulation (P < .001). ConclusionPatients whose cerebral saturation values measured with NIRS rise during CPR have a higher post-resuscitation survival rate. Monitoring of patients during CPR with this non-invasive technique may be a good method for predicting return of spontaneous circulation.

Sensitive and Robust Colorimetric Sensing of Sulfide Anion by Plasmonic Nanosensors Based on Quick Crystal Growth

A highly sensitive and selective method for colorimetric sensing of sulfide anions in aqueous solutions is illustrated. The sensing mechanism is based on quick crystallization from Ag to Ag2S in the presence of sulfide anions which alter the dielectric properties of the Au/Ag core/shell nanorods. The longitudinal surface plasmon resonance peak of the Au/Ag nanorods at about 686 nm undergoes a redshift and the color of the nanorod solution also changes from light green to purple. Sulfide ions at a concentration of 4.0 μM (1.3 ppb) can be detected visually and a sensitivity of 0.5 μM (167 ppt) is achieved by Vis–near-infrared spectrophotometry. Compared to other plasmonic sensors, our Au/Ag nanorod probe does not require surface modification while exhibiting high stability and robustness under different pH conditions. This simple and cost-effective sensing platform provides a rapid and convenient detection for sulfide anions at concentrations far below the hazardous limit in aqueous media.

In situ growth and ab initio optical characterizations of amorphous Ga3Se4 thin film: A new chalcogenide compound semiconductor thin film

This paper reports the first systematic study of the structural and optical characterization of Ga3Se4 thin film. Powder X-ray diffractometery analysis revealed that the films are amorphous. Optical reflection and transmittance measurements have been done by UV–visible–near-infrared spectrophotometry, and the values of various optical constants, such as the lower cut-off wavelength (550 nm), optical band gap (2.14 eV), dispersive energy (6.75 eV), oscillator energy (2.86 eV), static refractive index (1.83) and static dielectric constant (3.35), have been estimated.

THEH-BAND EMITTING REGION OF THE LUMINOUS BLUE VARIABLE P CYGNI: SPECTROPHOTOMETRY AND INTERFEROMETRY OF THE WIND

We present the first high angular resolution observations in the nearinfrared H-band (1.6 microns) of the Luminous Blue Variable star P Cygni. We obtained six-telescope interferometric observations with the CHARA Array and the MIRC beam combiner. These show that the spatial flux distribution is larger than expected for the stellar photosphere. A two component model for the star (uniform disk) plus a halo (two-dimensional Gaussian) yields an excellent fit of the observations, and we suggest that the halo corresponds to flux emitted from the base of the stellar wind. This wind component contributes about 45% of the H-band flux and has an angular FWHM = 0.96 mas, compared to the predicted stellar diameter of 0.41 mas. We show several images reconstructed from the interferometric visibilities and closure phases, and they indicate a generally spherical geometry for the wind. We also obtained near-infrared spectrophotometry of P Cygni from which we derive the flux excess compared to a purely photospheric spectral energy distribution. The H-band flux excess matches that from the wind flux fraction derived from the two component fits to the interferometry. We find evidence of significant near-infrared flux variability over the period from 2006 to 2010 that appears similar to the variations in the H-alpha emission flux from the wind. Future interferometric observations may be capable of recording the spatial variations associated with temporal changes in the wind structure.

Controlling the Plasmonic Properties of Supported 2D Arrays of Gold Nanocages

ABSTRACTThe enhancement of the plasmonic signatures, indicated by the shifting of the localized surface plasmon resonances, of three-dimensional, hollow, gold nanocages with respect to substrate nature and cage density is reported. The effect of substrate nature was investigated using absorbance, reflection, and transmission by ultraviolet-visible and near-infrared spectrophotometry. The gold nanocages were deposited on substrates as monolayers primarily by Langmuir-Blodgett technique. The density of the deposited monolayers and the nature of the surface of the substrates were determined using AFM and SEM/TEM imaging. The position of the LSPR signatures, primarily the dipolar plasmonic resonances, with respect to changing environment and nanostructure characteristics determined the tuneability of the plasmonic enhancements.

Fat content and fatty acid profiles of shea tree (Vitellaria paradoxa subspecies nilotica) ethno-varieties in Uganda

Fat content and fatty acid composition are important nutritional properties of shea fruits. Farmers in Uganda report the presence of local shea tree ethno-varieties, but it is necessary to investigate their relative fat content and fatty acid composition to evaluate the economic importance of these ethno-varieties. Near infrared spectrophotometry (NIRS) was used to determine the fat content as well as the fatty acid composition of 44 ethno-varieties. Wet chemistry (soxtec petroleum – ether fat extraction and gas chromatography) methods were used to validate the results from NIRS. Fat content ranged from 43.9% to 58.4% while fatty acid composition was dominated by oleic (47–62%) and stearic acid (25–38%). Other fatty acids present were palmitic, vaccenic, linoleic, linolenic and arachidic acids. There was no significant difference in stearic, palmitic and oleic acid composition between ethno-varieties. However, significant variation of fat content, vaccenic and linoleic acids was observed between some ethno-varieties, perhaps due to locality, climatic and tree-to-tree differences. These findings can be utilized for the selection of ethno-varieties that are suitable for commercial production of shea oil in Uganda.

22 Tissue Oxygenation in the Light of Non-Invasive and Continuous Near-Infrared Spectroscopy and Imaging (NIRS, NIRI)

Near-infrared spectrophotometry (NIRS) and imaging (NIRI) are quickly growing optical methods to non-invasively and in vivo study oxygenation of human tissue. NIRS and NIRI are appreciated by patients, relatives e.g....

Cerebral tissue hemoglobin saturation in children with sickle cell disease

Desaturation of hemoglobin (Hb) in cerebral tissue, a physiologic marker of brain vulnerable to ischemic injury, can be detected non-invasively by transcranial oximetry. Absolute cerebral oximetry has not been studied in sickle cell disease (SCD), a group at very high risk of cerebral infarction in whom prevention of brain injury is key. We measured absolute Hb saturation in cerebral tissue (S(CT)O(2)) in children with SCD using near-infrared spectrophotometry and investigated the contributions of peripheral Hb saturation (S(P)O(2)), hematologic measures, cerebral arterial blood flow velocity, and cerebral arterial stenosis to S(CT)O(2). We also assessed the effects of transfusion. We studied 149 children with SCD (112 HbSS/Sβ(0); 37 HbSC/Sβ(+)). S(CT)O(2) was abnormally low in 75% of HbSS/Sβ(0) and 35% of HbSC/Sβ(+) patients. S(CT)O(2) (mean ± SD) was 53.2 ± 14.2 in HbSS/Sβ(0) and 66.1 ± 9.2% in SC/Sβ(+) patients. S(CT)O(2) correlated with age, sex, Hb concentration, reticulocytes, Hb F, and S(P)O(2), but not transcranial Doppler arterial blood flow velocities as continuous measures. In multivariable models, S(P)O(2), Hb concentration, and age were significant independent determinants of S(CT)O(2). Cerebral vasculopathy was associated with ipsilateral cerebral desaturation. Transfusion increased S(CT)O(2) and minimized the inter-hemispheric differences in S(CT)O(2) due to vasculopathy. Cerebral desaturation, a physiologic marker of at-risk brain, is common in SCD, more severe in HbSS/Sβ(0) patients, and associated with peripheral desaturation, more severe anemia, and increasing age. Cerebral oximetry has the potential to improve the identification of children with SCD at highest risk of neurologic injury and possibly serve as a physiologic guide for neuroprotective therapy.

THEORETICAL SPECTRA OF TERRESTRIAL EXOPLANET SURFACES

We investigate spectra of airless rocky exoplanets with a theoretical framework that self-consistently treats reflection and thermal emission. We find that a silicate surface on an exoplanet is spectroscopically detectable via prominent Si-O features in the thermal emission bands of 7 - 13 \mu m and 15 - 25 \mu m. The variation of brightness temperature due to the silicate features can be up to 20 K for an airless Earth analog, and the silicate features are wide enough to be distinguished from atmospheric features with relatively high-resolution spectra. The surface characterization thus provides a method to unambiguously identify a rocky exoplanet. Furthermore, identification of specific rocky surface types is possible with the planet's reflectance spectrum in near-infrared broad bands. A key parameter to observe is the difference between K band and J band geometric albedos (A_g (K)-A_g (J)): A_g (K)-A_g (J) > 0.2 indicates that more than half of the planet's surface has abundant mafic minerals, such as olivine and pyroxene, in other words primary crust from a magma ocean or high-temperature lavas; A_g (K)-A_g (J) < -0.09 indicates that more than half of the planet's surface is covered or partially covered by water ice or hydrated silicates, implying extant or past water on its surface. Also, surface water ice can be specifically distinguished by an H-band geometric albedo lower than the J-band geometric albedo. The surface features can be distinguished from possible atmospheric features with molecule identification of atmospheric species by transmission spectroscopy. We therefore propose that mid-infrared spectroscopy of exoplanets may detect rocky surfaces, and near-infrared spectrophotometry may identify ultramafic surfaces, hydrated surfaces and water ice.

A readout for large arrays of microwave kinetic inductance detectors

Microwave kinetic inductance detectors (MKIDs) are superconducting detectors capable of counting single photons and measuring their energy in the UV, optical, and near-IR. MKIDs feature intrinsic frequency domain multiplexing (FDM) at microwave frequencies, allowing the construction and readout of large arrays. Due to the microwave FDM, MKIDs do not require the complex cryogenic multiplexing electronics used for similar detectors, such as transition edge sensors, but instead transfer this complexity to room temperature electronics where they present a formidable signal processing challenge. In this paper, we describe the first successful effort to build a readout for a photon counting optical/near-IR astronomical instrument, the ARray Camera for Optical to Near-infrared Spectrophotometry. This readout is based on open source hardware developed by the Collaboration for Astronomy Signal Processing and Electronics Research. Designed principally for radio telescope backends, it is flexible enough to be used for a variety of signal processing applications.

Cerebral Tissue Desaturation in Children with Sickle Cell Disease

Abstract 512 Background:Children with sickle cell disease (SCD) frequently suffer silent and overt cerebral infarction. Current screening and prevention techniques are suboptimal. Absolute cerebral oximetry is a rapid, non-invasive technique to measure hemoglobin (Hb) saturation in the brain. Cerebral tissue Hb saturation (SCTO2) is a physiologic measurement of the balance between oxygen supply and demand that could be used to identify regions of the brain at highest risk of infarction. We aimed to describe the distribution of SCTO2 in children with SCD and to identify its relationships with clinical, laboratory, and neuroimaging characteristics as well as response to transfusion. Methods:We used transcutaneous near-infrared spectrophotometry (CASMED FORE-SIGHT®) with bi-frontal probes to measure absolute SCTO2 in children with sickle cell anemia (SS), sickle-β0-thalassemia (Sβ0), sickle hemoglobin C disease (SC), and sickle-β+-thalassemia (Sβ+) during steady-state clinic visits or at the time of transfusion for stroke prophylaxis. Spearman correlation and multivariable modeling were used to test the relationships between SCTO2 and age, sex, genotype, Hb concentration, percent Hb F, percent reticulocytes, peripheral Hb saturation (SPO2), and cerebral arterial blood flow velocities by transcranial Doppler ultrasonography (TCD). Results:We studied 149 children (112 SS/Sβ0; 37 SC/Sβ+) with a mean age of 6.6±4.7 years (±S.D.). SCTO2 is known to be 65–80% in normoxic individuals with normal hemoglobin type and concentration breathing room air, but we found SCTO2 to be markedly lower in SCD: 53.2±14.2 (mean±SD) in SS/Sβ0 and 66.1±9.2% in SC/Sβ+ patients. SCTO2 was abnormally low (<65%) in 75% of SS/Sβ0 and 35% of SC/Sβ+ patients. SCTO2 correlated significantly with age (Spearman ρ=-0.54, P<0.001), sex (0.38, P<0.001), Hb concentration (0.38, P<0.001), percent reticulocytes (-0.3, P=0.002), percent Hb F (0.37, P<0.001), and SPO2 (0.4, P<0.001), but not TCD velocities as continuous measurements. However, when TCD velocities were categorized according to STOP criteria (abnormal and conditional vs. normal), SCTO2 was lower when the TCD velocity in the ipsilateral distal internal carotid artery was not normal (right-sided SCTO2: 39.2% for abnormal and conditional TCD vs. 57% for normal TCD, P=0.027). In multivariable models, the significant independent determinants of SCTO2 were SPO2 (P=0.004), Hb concentration (P=0.004), and age (P<0.001). Each unit decrease (1% absolute) in SPO2 gave an odds ratio of 1.4 or 1.5 for an abnormally low (<25th percentile) SCTO2 in the left and right hemispheres, respectively (AUC 0.84; P<0.001). Transfusion increased SCTO2 by 15.3% (absolute) on the left (P=0.002) and 23.6% (absolute) on the right (P=0.06). Two participants had severe unilateral cerebral vasculopathy demonstrated by magnetic resonance angiography. Both had a lower pre-transfusion SCTO2 on the side of the stenosis or occlusion (5-20% lower). The SCTO2 rose during the course of transfusion (10-30% absolute rise in SCTO2), and by the end of the transfusion the right- and left-sided SCTO2 measurements equalized. Conclusions:Cerebral tissue Hb desaturation is common in children with SCD and more severe in the SS/Sβ0 genotypes. Cerebral desaturation is associated with peripheral Hb desaturation, more severe anemia, increasing age, and occlusive vasculopathy, and it is ameliorated by transfusion. Cerebral desaturation, which can be detected rapidly and non-invasively, is a physiologic biomarker of brain at risk for ischemic injury. Cerebral oximetry should be studied further as a physiologic means to predict stroke and guide transfusion therapy for the prophylaxis of stroke in SCD. Disclosures:No relevant conflicts of interest to declare.

Cardiac displacement during off-pump coronary artery bypass grafting surgery: effect on sublingual microcirculation and cerebral oxygenation

Cardiac displacement during off-pump coronary artery bypass (OPCAB) surgery causes a fall in cardiac output. Here, we investigate how this drop in systemic perfusion is transferred to the oxygenation of sublingual and cerebral tissue. Sublingual microcirculatory perfusion or microcirculatory hemoglobin oxygen saturation (μHbSO(2)) measurements were performed using sidestream dark-field imaging and reflectance spectrophotometry, respectively (both n = 12). The cerebral tissue oxygenation index was measured by near-infrared spectrophotometry (n = 12). Cardiac output was calculated by pulse contour analysis of arterial pressure. Cardiac displacement reduced the cardiac output from 4.3 ± 0.8 to 1.2 ± 0.3 l/min (P < 0.05), paralleled by a decrease in μHbSO(2) from 64.2 ± 9.1 to 48.6 ± 8.7% (P < 0.01). Cardiac displacement did not change functional capillary density, while red blood cell velocity decreased from 895 ± 209 to 396 ± 178 μm/s (P<0.01). Cerebral tissue oxygenation index decreased from 69.5 ± 4.0 to 57.4 ± 8.5% (P<0.01) during cardiac displacement. After repositioning of the heart, all the values returned to baseline. Our data suggest that systemic hemodynamic alterations during cardiac displacement in OPCAB surgery reduce sublingual and cerebral tissue oxygenation. These findings are particularly important for patients at risk for the consequences of cerebral ischemia.

The Transparent Conductive Properties of Manganese-Doped Zinc Oxide Films Deposited by Chemical Bath Deposition

Manganese-doped zinc oxide (Mn-doped ZnO) thin films were prepared using chemical bath deposition (CBD), and the impacts of the manganese dopant concentration on the structure, electrical resistivity, optical transmission, and magnetic properties were investigated using x-ray diffractometry, Hall-effect measurements, ultraviolet–visible–near-infrared (UV–Vis–IR) spectrophotometry, and vibrating sample magnetometry (VSM), respectively. The concentration of the manganese dopant in the ZnO thin film critically impacted the resulting properties, and the 4.0 at.% Mn-doped ZnO film had a resistivity of 5.8 × 10−2 Ωcm, transmittance of 75.6% in the visible light range, and bandgap of 3.30 eV when the film was annealed at 600°C in an Ar + H2 atmosphere. Annealing the film could enhance its magnetic properties such that the film had a saturation magnetization of 21.0 emu/cm3 and a coercivity of 45.7 Oe after annealing at 600°C. Because of these electrical, optical, and magnetic properties, Mn-doped thin films are promising for use in spintronic devices.