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Author(s): J. Koteswara Rao [1]; Swati Chhabra (corresponding author) [1]; Sadik Mohammed [1]; Pradeep K. Bhatia [1]; Shilpa Goyal [1]; Rakesh Kumar [1] INTRODUCTION Hypotensive anaesthesia involves achieving a state [...], Background and Aims: There is limited literature wherein the hypotensive drugs have been compared to know the cerebral effects by monitoring regional cerebral oxygen saturation (rScO[sub.2]). This study aimed to compare the effects of dexmedetomidine and nitroglycerin on rScO[sub.2] during controlled hypotensive anaesthesia using near-infrared spectroscopy (NIRS). The primary objective was to evaluate the non-inferiority of dexmedetomidine versus nitroglycerin in the occurrence of cerebral desaturation events (CDEs) during hypotensive anaesthesia. Methods: Adult patients scheduled to undergo head and neck surgery under general anaesthesia randomised to receive either dexmedetomidine or nitroglycerin infusion for controlled hypotensive anaesthesia. Cerebral oximetry was monitored with NIRS, and data regarding CDEs, bilateral rScO[sub.2], and peri-operative haemodynamics were collected. Continuous data were analysed using unpaired Student&apos;s t-tests except for intra-group analyses, which were analysed using paired t-tests. Categorical data were analysed using the Chi-square test. For comparison of time to CDEs, Kaplan-Meier survival analysis with log-rank test was performed. Results: Of the 82 patients in both groups, CDEs were observed in 15 patients each. A decrease from baseline by 20% was observed in three patients: one in Group N and two in Group D. Statistically, there was an equal risk of getting CDEs in the groups. The time to CDE was comparable (P > 0.05). The difference in heart rate was statistically significant (P < 0.001). Conclusion: Dexmedetomidine is non-inferior to nitroglycerin in terms of the occurrence of cerebral desaturation events when used for controlled hypotensive anaesthesia in head and neck surgeries. Keywords: Cerebral desaturation events, dexmedetomidine, hypotensive anaesthesia, near-infrared spectroscopy, nitroglycerin, regional cerebral oxygen saturation

Author(s): Zeynep Serbest [sup.1] , Ozge Gorduk [sup.1] , Yucel Sahin [sup.1] Author Affiliations: (1) grid.38575.3c, 0000 0001 2337 3561, Yildiz Technical University, Faculty of Arts and Science, Department of [...], The aim of this study is to develop an electroanalytical method for the determination of serotonin, a very important neurotransmitter for neuroscience in food products, with an electrochemically produced sulfur-doped graphene oxide modified pencil graphite electrode (EGO/PGE). The S-doped graphene oxide electrode was fabricated by chronoamperometry, a fast, environmentally friendly, and, more importantly, functional group doping technique in one step. Techniques such as atomic force microscopy, electrochemical impedance spectroscopy, cyclic voltammetry, energy-dispersive X-ray spectroscopy, scanning electron microscopy, and Fourier-transform infrared spectroscopy were used for the structural and morphological characterization of the produced sensor. The limit of detection and limit of quantitation were calculated as 0.026 and 0.09 [micro]M, respectively, using differential pulse voltammetry under optimum experimental conditions with the prepared EGO/PGE. Recovery tests were performed by spiking different concentrations into walnut and milk samples to investigate the applicability of the developed method in food samples. Good results between 93.1 and 105.8% were obtained in recovery studies. These results showed that the developed S-doped graphene oxide modified pencil graphite electrode platform was practically applicable in food samples due to its simplicity, low cost, fast response time, easy manufacturing, good selectivity, and high sensitivity.

Author(s): De Fang [sup.1] [sup.2] [sup.3] Caihong Lv [sup.4] [sup.5] Author Affiliations: (1) grid.162110.5, 0000 0000 9291 3229, Center for Materials Research and Analysis, Wuhan University of Technology, , 430070, [...], Automotive paint flakes are significant for the forensic scientists to use as the evidence for forensic purposes. Conducting the multichannel and scientific characterization and comparison of them is in urgent need to draw objective and fair conclusions, demonstrating the fair and equitable administration of justice. With the help of infrared spectroscopy (IR), Raman spectroscopy (Raman), scanning electron microscopy (SEM), energy disperse spectroscopy (EDS) and stereomicroscopy, the properties of three paint flakes from automobiles at the scene of the accident have been studied for forensic purposes in this paper. Primary discussion is progressed according to the stereomicroscope and SEM images, while the in-depth conclusion is proved by the component analysis acquired with EDS, IR and Raman. Furthermore, colors, thickness, sequence, microstructure and composition of layers provide much significant information. The third layers of all the samples show the significant changes clearly, indicating that sample C is different from samples A and B. However, the first, second and fourth layers give rise to consistent analysis profiles. The results of this study provide the significant fundamental information which can be used to analyze the paint flakes for forensic scientists.

The synthesis and characterisation (IR, NMR, HR-MS, and X-ray crystallography) of six oxazoline Zn complexes, containing enolate ligands derived from a series of (Z)-1-R-2-(4',4'-dimethyl-2'-oxazolin-2'-yl)-efh-1-en-1-ols (R=[C.sub.6][H.sub.5], [C.sub.6][H.sub.4]-p-N[O.sub.2], [C.sub.6][H.sub.4]-p-O[CH.sub.3], [CF.sub.3], [CH.sub.3], or [CMe.sub.3]) is detailed. All derivatives are air-stable solids of formula Zn[([L.sup.n]).sub.2] and are formed in the presence of the title ligands and [NEt.sub.3]. Reasonable yields (53%-82%) are obtained with the exception of R= [CMe.sub.3] (9%); in this case, by-product formation and high solubility affected complex isolation. Crystallographic characterisation reveals that in all cases the ligands are bound in a [kappa].sup.2]-N, O-bonding motif. Little structural diversity is noted within the series; these complexes are further placed into structural context with related Zn materials containing oxazoline, phenolate, and (or) Schiff base ligands. Key words: oxazoline, coordination complexes, zinc, enolate, X-ray crystal structure, Introduction The naturally occurring Group 12 elements hold a unique position within coordination chemistry due to the overwhelming predominance of the +2 oxidation state. This is, of course, a result [...]

Author(s): Masoud Giahi [sup.1] , Masoomeh Sayyar Ardaki [sup.2] , Gholamreza Vaghar [sup.3] , Majid Arvand [sup.2] Author Affiliations: (1) grid.411463.5, 0000 0001 0706 2472, Department of Chemistry, South Tehran [...], A novel chemically modified carbon paste electrode based on an inexpensive Ni(salph) complex, where salph is N,N&apos;-bis(salicylidene)-4-methyl-o-phenylenediimine, was prepared for the simultaneous determination of guanine, adenine and thymine. The electrode was characterized by Fourier-transform infrared spectroscopy, field emission scanning electron microscopy, X-ray diffraction, energy dispersive X-ray analysis, thermogravimetric analysis and cyclic voltammetry. The proposed sensor enhanced the anodic peak currents of the nucleobases and could determine them sensitively in 0.1 M phosphate buffer solution (pH 7.0). Moreover, well-separated voltammetric peaks were obtained for guanine, adenine and thymine present in the analyte mixture. Under the optimum operating conditions, the peak currents for guanine, adenine and thymine increased linearly with the increase in the analyte mixture concentration in the ranges of 0.1 to 80, 0.1 to 50 and 15 to 150 [mu]M, respectively. The detection limits for guanine, adenine and thymine were 0.03, 0.03 and 5 [mu]M, respectively. This new approach has been successfully applied for the detection of the corresponding targets in a DNA sample with acceptable recovery.

Author(s): E. V. Bizina [sup.1] , O. V. Farafonova [sup.1] , N. I. Zolotareva [sup.2] , S. S. Grazhulene [sup.2] , T. N. Ermolaeva [sup.1] Author Affiliations: (1) grid.459699.e, 0000 [...], Conditions for the formation of a recognition layer of a piezoelectric immunosensor based on magnetic carbon nanocomposites (MCNCs) under the action of an external magnetic field are studied. The effects of the size and number of magnetic nanoparticles (MNPs) in the composite on the analytical characteristics of the gravimetric immunosensor are revealed. Scanning electron microscopy is used to determine the average sizes of Fe.sub.3O.sub.4 magnetic nanoparticles synthesized by coprecipitation. It is noted that the minimum weight and stability of the recognition layer were observed for the nanocomposite obtained at a ratio of carbon nanotubes and MNPs with an average diameter of 22 nm equal to 3 : 1. The formation of peptide bonds between the MCNCs and a penicillin G conjugate was established by IR spectrometry. It was shown that the use of magnetic carbon nanocomposites in the formation of a recognition layer makes it possible to significantly simplify the procedure for preparing a piezoelectric sensor for analysis and reduce its duration from 24 to 1.5 h. The range of the determined antibiotic concentrations is 1-450 ng/mL, the limit of detection is 0.5 ng/mL.

Author(s): M. Yu. Larina [sup.1] , O. V. Farafonova [sup.1] , S. A. Eremin [sup.2] , T. N. Ermolayeva [sup.1] Author Affiliations: (1) grid.459699.e, 0000 0001 0096 2646, Lipetsk State [...], Conditions are studied for the synthesis of carbon quantum dots (CQD) exhibiting green fluorescence by the ultrasonic treatment of multilayered carbon nanotubes in a mixture HNO.sub.3 with H.sub.2SO.sub.4 (CQD-1) and by the microwave decomposition of 9,10-dinitroanthracene in ethanol (CQD-2). The sizes of COD are estimated by atomic force microscopy, and their optical properties, by spectrophotometry and fluorescence spectrometry. Infrared spectrometry was used to identify active functional groups on the CQD surface, participating in the formation of stable bonds in the synthesis of tracers. A possibility of using CQD as labels in fluorescence polarization immunoassay (FPIA) is shown. Procedures are developed for determining aminoglycoside antibiotics gentamycin, streptomycin, and amikacin by FPIA using a TDx-analyzer (Abbott Diagnostics, United States); their performance characteristics are presented. The limit of detection is (ng/mL) 20, 10, and 3, and the analytical range ([micro]g/mL) is 0.05-3.00, 0.02-6.00, and 0.01-3.00 for gentamycin, streptomycin, and amikacin respectively. The procedures are tested in the determination of gentamycin, streptomycin, and amikacin in dairy products.

Phenylacetylene was inserted and polymerized in 5 nm diameter silica nanotubes under high pressure-high temperature conditions of 0.5 GPa and 437 K in an inert gas. The resulting nanocomposite was characterized by infrared and Raman spectroscopy and scanning and transmission electron microscopy. The vibrational spectroscopic data confirmed the formation of [pi]-conjugated polyphenylacetylene and the absence of crystallization of the amorphous nanotubes. Scanning transmission electron microscopy coupled with energy dispersive X-ray spectroscopy, STEM-EDX, measurements confirmed the insertion of the polymer in the channels of the nanotubes and electron diffraction confirmed the amorphous nature of both the polymer and the host Si[O.sub.2] nanotubes. The obtained nanocomposite is a candidate material for gas sensing applications. Key words: silica nanotubes, polymer, high pressure, transmission electron microscopy, Raman spectroscopy. Du phenylacetylene a ete insere puis polymerise dans des nanotubes de silice de diametre 5 nm dans de conditions de haute pression 0,5 GPa et haute temperature 437 K. Le nanocomposite obtenu a ete caracterise par spectroscopies infrarouge et Raman et par microscopies electronique a balayage et en transmission. Les donnees de spectroscopie vibrationnelle ont confirme la formation de polyphenylacetylene n-conjugue ainsi que l'absence de cristallisation des nanotubes amorphes. La microscopie electronique en transmission a balayage, couplee a la spectroscopie des rayons X en dispersion d'energie a confirme Tinsertion du polymere a l'interieur des canaux des nanotubes. La diffraction electronique a confirme la nature amorphe du polymere et des nanotubes de Si[O.sub.2] hote. Le nanocomposite est un candidat comme materiau pour les capteurs de gaz. Mots-cles: nanotubes de silice, polymere, haute pression, microscopie electronique en transmission, spectroscopie Raman., Introduction Polyphenyacetylene (1-10)has attracted particular attention over the past decades as a p-conjugated system, which can be used as a conducting polymer. Conducting polymers present a considerable interest for applications [...]

In the present study, for the first time, walnut bloom (WB) powder was used as a natural and economic sorbent for the removal of methylene blue (MB) from an aqueous solution. This new biosorbent was characterized using the following techniques: scanning electron microscopy (SEM), X-ray diffraction (XRD), COHNS, BET (Brunauer-Emmett-Teller) analysis, and Fourier transform infrared (FTIR) spectroscopy. MB removal efficiency and its adsorption onto WB powder were tested in a batch system by varying parameters such as initial dye concentration, contact time, pH, temperature, and dosage of biosorbent in which the removal percentages of ~92% was achieved under the optimum conditions. Equilibrium data and adsorption isotherms fit well with the Langmuir model ([R.sup.2] - 0.999, 0 < [R.sub.L] < 1) with a maximum monolayer adsorption capacity of 46 mg [g.sup.-1]. The chemical kinetics of MB adsorption followed the pseudo second-order model. Also, the magnitude of thermodynamic functions identified the removal of MB. [DELTA]Ho of-7.32 kJ [mol.sup.-1] and [DELTA]So of-4.32 kJ [mol.sup.-1] indicated the spontaneity, exothermicity, and favorability of the adsorption process at room temperature. Key words: methylene blue, removal, walnut bloom powder. Dans le cadre de la presente etude, nous avons ete les premiers a utiliser la poudre de fleurs de noyer (FN) comme sorbant naturel et economique pour l'elimination du bleu de methylene (BM) d'une solution aqueuse. Nous avons caracterise ce nouveau biosorbant a l'aide des techniques suivantes: microscopie electronique a balayage (MEB), diffraction des rayons X (DRX), analyses par la methode de Cohns et la methode de Brunauer-Emmett-Teller (BET) et spectroscopie infrarouge a transformed de Fourier (FTIR). Nous avons evalue l'efficacite de l'elimination du BM et son adsorption sur la poudre de FN dans un systeme de traitement par lots en faisant varier les parametres tels que la concentration initiale du colorant, le temps de contact, le pH, la temperature et la quantite du biosorbant, avec lequel des pourcentages d'elimination d'environ 92 % ont ete atteints en conditions optimales. Les donnees d'equilibre et les isothermes d'adsorption concordaient bien avec le modele de Langmuir ([R.sup.2] - 0,999; 0 < [R.sub.L] < 1), pour une capacite maximale d'adsorption monocouche de 46 mg*[g.sup.-1]. La cinetique de l'adsorption chimique du BM suit le modele de pseudo-second ordre. De plus, l'ordre de grandeur des fonctions thermodynamiques Concorde avec l'elimination du BM. Le [DELTA]?o de -7,32 kJ [mol.sup.-1] et le [DELTA]So de 4,32 kJ [mol.sup.-1] indiquent un processus d'adsorption spontane, exothermique et favorable a temperature ambiante. [Traduit par la Redaction] Mots-cles: bleu de methylene, elimination, poudre de fleurs noyer., Introduction 3,7-Bis(Dimethylamino)-phenothiazine-5-ium chloride or methylene blue (MB) is a heterocyclic aromatic compound that is widely used in a range of different fields, especially in the textile industry. (1) As most [...]

Heart failure is the most common cause of hospital admissions in North America, with more than 6 million patients accounting for $31 billion in healthcare cost in the US alone [...], * Context.--Myocardial fibrosis underpins a number of cardiovascular conditions and is difficult to identify with standard histologic techniques. Challenges include imaging, defining an objective threshold for classifying fibrosis as mild or severe, and understanding the molecular basis for these changes. Objective.--To develop a novel, rapid, label-free approach to accurately measure and quantify the extent of fibrosis in cardiac tissue using infrared spectroscopic imaging. Design.--We performed infrared spectroscopic imaging and combined that with advanced machine learning-based algorithms to assess fibrosis in 15 samples from patients belonging to the following 3 classes: (1) patients with nonpathologic (control) donor hearts, (2) patients undergoing transplant, and (3) patients undergoing implantation of a ventricular assist device. Results.--Our results show excellent sensitivity and accuracy for detecting myocardial fibrosis, as demonstrated by a high area under the curve of 0.998 in the receiver operating characteristic curve measured from infrared imaging. Fibrosis of various morphologic subtypes were demonstrated with virtually generated picrosirius red images, which showed good visual and quantitative agreement (correlation coefficient = 0.92, p = 7.76 x [10.sup.-15]) with stained images of the same sections. Underlying molecular composition of the different subtypes was investigated with infrared spectra showing reproducible differences presumably arising from differences in collagen subtypes and/or crosslinking. Conclusions.--Infrared imaging can be a powerful tool in studying myocardial fibrosis and gleaning insights into the underlying chemical changes that accompany it. Emerging methods suggest that the proposed approach is compatible with conventional optical microscopy, and its consistency makes it translatable to the clinical setting for real-time diagnoses as well as for objective and quantitative research.

Copoly-propylene glycol (terephthalate-maleate) based unsaturated polyester resin (UPER) was modified with nadimide end-capped polyether telechelics namely, polypropylene glycol (PPG with molecular weight 2000, 1000, 400 g/mol), polytetramethylene oxide (PTMO with molecular weight 2000 g/mol) and polyethylene glycol (PEG with molecular weight 2000 g/mol) (NPPG/NPTMO/NPEG). The telechelic NPPG/NPTMO/NPEG were synthesized from the corresponding polyols (hydroxy telechelics) by reaction with 4-nadimido benzoyl chloride. These derivatives were characterized by chemical and spectral methods. Blends of UPER with varying amounts of NPPG/NPTMO/NPEG were prepared. Blending boosted the cohesive energy through enhanced crosslinking as reflected in the gel content of the cured matrices done in separate studies. It increased the fracture characteristics tremendously. The addition of 2.5 phr of the nadimide end functional polyether gave the maximum toughness. The crosslink density showed an initial increase on blending, but further addition of the telechelics did not make any change. The properties of the prepared blends were compared with maleimide end-capped polyether toughened UPE resins. It was concluded that the toughening effect of the polyether additive depends not only on its concentration but also on its distribution in the matrix as dictated by its reactivity ratio with styrene. The high reactivity of the nadimide groups did not create an ambiance good enough to get an acceptable distribution of the polyether segments conducive for a tough matrix. Whereas the maleimide end-capped polyether provides better toughening efficiency. KEYWORDS nadimide, polyether telechelics, thermosetting resins, toughening, unsaturated polyester resin, 1 | INTRODUCTION Unsaturated polyester (UPE) resins are well-known thermosetting resins and are extensively used in the market because of their exceptional properties and cost-efficacy. However, the cross-linked UPE resins [...]

Author(s): Chunyan Wang [sup.1], Dan Ding [sup.1], Xiaoqing Jiang [sup.1], Bo Zhou [sup.1] Author Affiliations: (1) grid.260474.3, 0000 0001 0089 5711, Jiangsu Key Laboratory of New Power Batteries, Jiangsu Collaborative [...], Bimetallic porphyrin coordination polymers with various Cu/Cd ratios (Cu-Cd) were synthesized and characterized by X-ray diffraction, infrared spectroscopy, inductively coupled plasma atomic emission spectrometry and transmission electron microscopy. The presence of Cu(II) in the series of bimetallic porphyrin coordination polymers makes them electrochemically active, consequently, they can be used in electrochemical sensing of hydrogen peroxide and sodium nitrite. Their sensing performance was investigated by cyclic voltammetry and chronoamperometry. The performance was affected by Cu/Cd ratio of Cu-Cd, and the optimal Cu-Cd-2 (with Cu/Cd ratio of 1.59) showed the best performance: the detection sensitivities for H.sub.2O.sub.2 and NaNO.sub.2 were 414 and 418 mA/(M cm.sup.2), respectively, and detection limits were 2.7 and 3 [mu]M (S/N = 3). These results demonstrate that Cu-Cd offers great prospect for the construction of non-enzymatic sensors for hydrogen peroxide or sodium nitrite.

Diglycidyl ether Schiff base monomers were prepared from vanillin and various diamines. FT-IR, [sup.1]H NMR, [sup.13]C NMR, and mass spectroscopy were used to determine their structure. Cured thermoset epoxies made with them were compared to commercial epoxy in terms of mechanical properties. Tensile strengths ranged from 35.1 to 60.4 MPa, Young's modulus from 3.9 to 6.9 GPa, similar to the commercial product. The glass transition ranged from 80 to 117[degrees]C, the phase transition [T.sub.[alpha]] from 80 to 121[degrees]C and the storage modulus from 2 to 3.5 GPa. Thermogravimetric analysis showed that the vanillin-based epoxies were less heat resistant but had higher residual mass (20-30% wt/wt). Hydrolysis, hydrophobicity and degradation were also monitored to evaluate their potential for coating applications. KEYWORDS biosourced, bisphenol A, epoxy, thermoset, vanillin, 1 | INTRODUCTION Thermoset plastics are used widely in coating and composite applications, due to their high strength modulus and resistance to heat and chemical hydrolysis. [1-5] They are characterized [...]

As one of mature enhanced oil recovery (EOR) technologies, polymer flooding has been extensively applied in oilfield. In this study, new hydrophobically associative copolymers were synthesized by free-radical polymerization of acrylamide (AM), acrylic acid (AA), vinyl-modified p-cyclodextrins, and a water-soluble hydrophobic macromonomer (AA-APE-20). Fourier transform infrared, protonnuclear magnetic resonance, and scanning electron microscopy verified the structure of hydrophobically associative polymers (HDAPAMs). Compared with partially hydrolyzed polyacrylamide (HPAM), multiple intermolecular forces including chelation between ethoxyl (EO) group and [Ca.sup.2+]/[Mg.sup.2+], electrostatic bridges between EO groups and carboxyl groups (--COO-), hydrogen bonding between EO groups and AM groups (--CO[NH.sub.2]), hydrophobic association among nonyl phenol groups, and host-guest inclusion interaction endowed HDAPAMs favorable temperature-resistance, salt-resistance, and displacement efficiency. It was found that HDAPAMs showed evident temperature-response, salt thickening effect, favorable thixotropy, and viscoelasticity. Compared with HPAM, the core flooding experiments demonstrated that HDAPAMs could further enhance 6.97% to 8.43% oil recovery, even after HPAM flooding used. All the results revealed the EOR potential in HDAPAMs flooding. KEYWORDS EOR, flow behavior, hydrophobically associative copolymers, multiple intermolecular forces, rheological properties, 1 | INTRODUCTION As one of enhanced oil recovery (EOR) techniques in oilfields, polymer flooding has been extensively used for several decades for its obvious effect on increasing oil production [...]

High-dielectric constant (high-K) polymer nanocomposites based on nematic liquid crystals and Ca[Cu.sub.3][Ti.sub.4][O.sub.12] (CCTO) nanoparticles have been prepared. The host matrix is polymer dispersed liquid crystals (PDLC) in which LC (E7) droplets are dispersed in different polymer blends ratios of poly vinyl chloride/poly aniline (PVC/PANI). The PDLC (PVC/PANI/E7) in the appropriated ratios; (90/10/5), (75/25/5), and (50/50/5) were composited with 10 wt % CCTO nanoparticles. The IR spectra recorded for the PDLC nanocomposites present a spectrum similar to that of pure PDLC but with a slight shift of the peak positions. The addition of PANI and CCTO to PDLC enhances the thermal stability of the nanocomposites. SEM demonstrates agglomerates of CCTO dispersed in the polymer textures. Moreover, the addition of E7 facilitates the integration of PANI in PDLC matrix. The broadband dielectric spectrum shows high-frequency relaxation in addition to low-frequency interfacial polarization (Maxwell-Wagner type polarization). Besides, [epsilon]' at 50 Hz is in the order of 105 for PDLC/CCTO (50/50/5/10) nanocomposite. In addition, the computed energy density is found to be 74.66 J/[cm.sup.3]. This presumed ratio could be accentuated as a potential candidate for energy storage application with respect to the considerations of device fabrications. KEYWORDS calcium copper titanate CCTO nanoparticies, conductivity, dielectric properties, energy density, liquid crystal, poly aniline, poly vinyl chloride, polymer dispersed liquid crystals, 1 | INTRODUCTION Potential materials with high-dielectric constant (high-k) and excellent flexibility are vital for many electronic applications and devices, such as memory, power systems, and energy storage capacitors. [1,2] [...]

Author(s): Keika Mukaihara [sup.1] , Maiko Hasegawa-Moriyama [sup.1] , Yuichi Kanmura [sup.1] Author Affiliations: (1) Department of Anesthesiology and Critical Care Medicine, Graduate School of Medical and Dental Sciences, Kagoshima [...], Purpose Perioperative analgesia during thoracotomy is often achieved by combining paravertebral block (PVB) with general anesthesia (GA). Functional near-infrared spectroscopy (NIRS) can detect changes in cerebral oxygenation resulting from nociceptive stimuli in the awake state or under sedation. We used NIRS to measure changes in cerebral blood flow provoked by thoracotomy incision made under GA and determine how these changes were influenced by supplementation of GA with PVB. Methods Thirty-four patients undergoing elective thoracotomy were enrolled. Patients were randomly assigned to a group receiving only GA, or GA combined with PVB (GA + PVB). Changes in cerebral oxygenated hemoglobin ([DELTA]O.sub.2Hb), deoxygenated-Hb ([DELTA]HHb), and total-Hb ([DELTA]totalHb) were evaluated by NIRS as surgery began. Results In the GA group, [DELTA]O.sub.2Hb was significantly higher in the hemisphere contralateral to the side of surgery when the incision was made and 2 min after incision compared with the ipsilateral side (start of surgery, P < 0.01; 2 min, P < 0.05). In contrast, there were no significant changes in the [DELTA]O.sub.2Hb at any of the time points in the GA + PVB group. Comparable with [DELTA]O.sub.2Hb, the concentration of [DELTA]totalHb was significantly higher in the contralateral hemisphere in the GA group at the start of surgery (P < 0.05). Conclusions Changes in the cerebral O.sub.2Hb concentration were detected by NIRS immediately after surgical incision under GA, but not in the presence of a PNB. NIRS could be used to monitor surgical pain. PVB inhibited changes in oxygenation induced by incision-provoked pain.

Despite strong evidence for the importance of charcoal as a long-term carbon sink in soils, simple methods to quantify charcoal in soil are still lacking. In this study, we tested the application of attenuated total reflectance mid-infrared spectroscopy (ATR-MIR) for quantification of charcoal in soil. To do this, we created calibration samples from defined quantities of pulverised rock, charcoal and litter sampled from a forest floor in Guy Fawkes National Park, New South Wales, Australia, and analysed them via ATR-MIR and dry combustion. The organic carbon concentration (mass proportion) of the samples ranged from 0.1 to 15% and the charcoal mass proportion from 0.02-11 % (10-50% of soil organic matter). We then trained randomForcst models to the spectral data and assessed the predictive performance of the models for both the quantity of charcoal and litter in the samples. The models were excellent at predicting both charcoal and litter contents of the samples, explaining 94% of variance in the mass proportion of charcoal and 93% of the variance in the litter content of the validation dataset (i.e. out-of-bag estimates of the models). Extracting the variable importance from the models showed that the spectral regions important to charcoal prediction differed from those important to litter prediction, highlighting the capacity of the models to distinguish between charcoal and litter components based upon ATR-MIR spectra. Our method enables a simple, cheap and efficient prediction of litter and charcoal without the need for complex chemical extraction or analyses. Additional keywords: ATR-MIR black carbon, machine learning, randomForest, soil pyrogenic matter., Introduction Pyrogenic carbon--also referred to as black carbon--is a product of the incomplete combustion of organic matter. Charcoal is a particulate form of pyrogenic carbon, which can be well preserved [...]

Oxidative stress (OS)--an imbalance of pro-oxidants and antioxidants in favor of the former ones--is the cause of a number of diseases, for example, neurodegenerative diseases, metabolic syndrome, diabetes, etc. The [...], We proposed a procedure for the IR spectrometric determination of lipid hydroperoxides in biological systems. The main bands in the IR absorption spectra of linoleic acid and its hydroperoxide were identified, and analytical bands suitable for the determination of both compounds in their mixtures were selected. It was demonstrated that tert-butyl hydroperoxide can be used as an external standard for determining fatty acid hydroperoxides. Using the external standard method (calibration curve) for tert-butyl hydroperoxides, we calculated the concentration of linoleic acid hydroperoxide in its mixture with linoleic acid; it agreed with the specified values. Using the developed procedure, we estimated the concentration of hydroperoxide groups in natural cardiolipin. The results were compared to those obtained by an independent method (activated chemiluminescence). Keywords: lipid peroxidation, lipid hydroperoxides, linoleic acid, linolenic acid hydroperoxide, tert-butyl hydroperoxide, tetraoleoyl cardiolipin, bovine cardiolipin, IR spectrometry