Binder-free all-carbon composite supercapacitors

Carbon-based electrode materials have widely been used in supercapacitors. Unfortunately, the fabrication of the supercapacitors includes a polymeric binding material that leads to an undesirable addition of weight along with an increased charge transfer resistance. Herein, binder-free and lightweight electrodes were fabricated using powder processing of carbon nanofibers (CNFs) and graphene nanoplatelets (GNPs) resulting in a hybrid all-carbon composite material. The structural, morphological, and electrochemical properties of the composite electrodes were studied at different concentrations of GNPs. The specific capacitance (Cs) of the CNFs/GNPs composite was improved by increasing the concentration of GNPs. A maximum Cs of around 120 F g-1was achieved at 90 wt% GNPs which is around 5-fold higher in value than the pristine CNFs in 1 M potassium hydroxides (KOH), which then further increased to 189 F g-1in 6 M KOH electrolyte. The energy density of around 20 Wh kg-1with the corresponding power density of 340 W kg-1was achieved in the supercapacitor containing 90 wt% GNPs. The enhanced electrochemical performance of the composite is related to the presence of a synergistic effect and the CNFs establishing conductive/percolating networks. Such binder-free all-carbon electrodes can be a potential candidate for next-generation energy applications.

COVID-19 vaccine coverage, determinants and inequity amongst refugees and migrants in Pakistan: a cross-sectional study

OBJECTIVE

Migrants and refugees are at a disadvantage in accessing basic necessities. The objective of this study is to assess the inequity in access, needs and determinants of COVID-19 vaccination among refugees and migrant populations in Pakistan.

DESIGN

We conducted a mixed-method study comprising a cross-sectional survey and a qualitative study. In this paper, we will only report the findings from the cross-sectional survey.

SETTING

This survey was conducted in different cities of Pakistan including Quetta, Karachi and Hyderabad.

PARTICIPANTS

A total of 570 participants were surveyed including refugees and migrants, both in regular and irregular situations.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome of the study was to estimate the proportion of refugees and migrants, both in regular and irregular situations vaccinated against COVID-19 and assess the inequity. The χ2 test and Fisher's exact test were used to determine the significant differences in proportions between refugees and migrants and between regions.

RESULTS

The survey showed that only 26.9% of the refugee and migrant population were tested for COVID-19, 4.56% contracted coronavirus, and 3.85% were hospitalised due to COVID-19. About 66% of the refugees and migrants were fully vaccinated including those who received the single-dose vaccine or received all two doses, and 17.6% were partially vaccinated. Despite vaccination campaigns by the government, 14.4% of the refugee and migrant population remained unvaccinated mostly because of vaccines not being offered, distant vaccination sites, limited access, unavailability of COVID-19 vaccine or due to a difficult registration process. Vaccination rates varied across provinces, genders and migrant populations due to misconceptions, and several social, cultural and geographical barriers.

CONCLUSION

This study highlights the COVID-19 vaccine coverage, access and inequity faced by refugees and migrants during the pandemic. It suggests early prioritisation of policies inclusive of all refugees and migrants and the provision of identification documents to ease access to basic necessities.

An investigation of Ca-doped MgO nanoparticles for the improved catalytic degradation of thiamethoxam pesticide subjected to visible light irradiation

The remediation of pesticides from the environment is one of the most important technology nowadays. Herein, magnesium oxide (MgO) nanoparticles and calcium-doped magnesium oxide (Ca-doped MgO) nanoparticles were synthesized by the co-precipitation method and were used for the degradation of thiamethoxam pesticide in aqueous media. Characterization of the MgO and Ca-doped MgO nanoparticles were performed by XRD, SEM, EDX, and FT-IR analysis to verify the synthesis and variations in chemical composition. The band gap energy and crystalline size of MgO and Ca-doped MgO nanoparticles were found to be 4.8 and 4.7 eV and 33 and 34 nm respectively. The degradation of thiamethoxam was accomplished regarding the impact of catalyst dosage, contact time, temperature, pH, and initial pesticide concentration. The pH study indicates that degradation of thiamethoxam depends on pH and maximum degradation (66%) was obtained at pH 5 using MgO nanoparticles. In contrast, maximum degradation (80%) of thiamethoxam was observed at pH 8 employing Ca-doped MgO nanoparticles. The percentage degradation of thiamethoxam was initially increasing but decreased at higher doses of the catalysts. The degradation of the pesticide was observed to be increased with an increase in contact time while high at room temperature but decreased with a temperature rise. The effect of the initial concertation of pesticide indicates that degradation of pesticide increases at low concentrations but declines at higher concentrations. This research study reveals that doping of MgO nanoparticles with calcium enhanced the degradation of thiamethoxam pesticide in aqueous media.

Enhancement of photocatalytic activity of Ba-doped CoO for degradation of Emamectin benzoate in aqueous solution

The present study was focused on the preparation of cobalt oxide (CoO) and barium-doped cobalt oxide (Ba-doped CoO) by following the co-precipitation method for the degradation of Emamectin benzoate pesticide in the aqueous medium. The prepared catalysts were characterized using SEM, EDX, and XRD to confirm the formation of catalysts and to observe the variation in the composition of catalysts during the degradation study. It can be suggested from the results of SEM, EDX, XRD, and FTIR analyses that Ba atom has successfully incorporated in the crystalline structure of CoO. The degradation of Emamectin benzoate pesticide was studied under the influence of different factors like solution pH, the dose of catalyst, contact time, temperature, and initial concentration of pesticide. It was observed that solution pH affects the degradation of the pesticide, and maximum degradation (23% and 54%) was found at pH 5.0 and 6.0 using CoO and Ba-doped CoO, respectively. The degradation of pesticides was found to be increased continuously (27-35% in case of CoO while 47-58% in case Ba-doped CoO) with the time of contact. However, the degradation was found to be decreased (23-3% in case of CoO while 47-44% in case Ba-doped CoO) with an increase in temperature. Likewise, in the beginning, degradation was observed to be increased up to some extent with the dose of catalyst and initial concentration of pesticide but started to decrease with further augmentation in the dose of catalyst and initial concentration of pesticide. It may be concluded from this study that doping of Ba considerably enhanced the photocatalytic ability of CoO for Emamectin benzoate pesticide.

Synthetic Potential of Regio- and Stereoselective Ring Expansion Reactions of Six-Membered Carbo- and Heterocyclic Ring Systems: A Review

Ring expansion reactions fascinate synthetic chemists owing to their importance in synthesizing biologically active compounds and their efficacy in medicinal chemistry. The present review summarizes a number of synthetic methodologies, including stereoselective and regioselective pathways adopted by scientists, for framing medium- to large-size carbo- and heterocycles involving lactams, lactone, azepine and azulene derivatives via ring expansion of six-membered carbo- and heterocycles that have been reported from 2007–2022. Numerous rearrangement and cycloaddition reactions involving Tiffeneau–Demjanov rearrangement, Aza–Claisen rearrangement, Schmidt rearrangement, Beckmann rearrangement, etc., have been described in this regard.

Mixed micellar solubilization for procion blue MxR entrapment and optimization of necessary parameters for micellar enhanced ultrafiltration

In this study, micellar enhanced ultrafiltration, MEUF, being an active methodology, has been employed to remove Procion Blue MxR (PBM) from synthetic effluent. MEUF is being applied to reduce the toxicity level of aqueous system using the micellar media of cationic surfactants i.e. Cetyl trimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPC). Subsequently, the effect of addition of nonionic surfactant, Triton X-100 (TX-100), on solubilizing power of cationic surfactants is investigated. The values of partition coefficient and free energy of partition reflect the extent of interaction of the dye with the surfactants. Initially molecules of pollutants i.e. dye form ion pairs with ionic surfactants and, later on, the same is incorporated within micelle. Maximum value of free energy of partition ΔG_p has been found to be -55.49 kJmol^-1 and -50.43 kJmol in the presence of CPC and CTAB, respectively. The size of pollutant, thus, increases and, consequently, can be easily filtered. The effect of various factors i.e. concentration of surfactant, concentration of electrolyte (NaCl), transmembrane pressure, revolutions per minute (RPM) and pH, have been investigated to find the optimum conditions for maximum removal of PBM from aqueous system. The efficiency of MEUF has been assessed by calculating the values of rejection percentage and permeate flux. Both the surfactants were observed as strong candidates for PBM encapsulation but overall, maximum rejection percentage (R%) of 96.90% was attained by CPC.

Biosorption of metribuzin pesticide by Cucumber (Cucumis sativus) peels-zinc oxide nanoparticles composite

Herein, a biosorbent was prepared from cucumber peels modified with ZnO nanoparticles (CPZiONp-composite) for the biosorption of metribuzin. Characterization of the composite was accomplished using FTIR, SEM, EDX, surface area pore size analyzer and pH of point of zero charge (pH_pzc). Biosorption study was executed in batch concerning the impact of pH, composite dose, contact time, initial metribuzin concentration and temperature. The biosorption depends on pH and maximum biosorption was acquired at pH 3.0. Surface chemistry of the composite was studied by determining the pH_pzc and was found to be 6.1. The biosorption nature was investigated using isotherms and was assessed that Freundlich isotherm is well suited for the fitting of the biosorption data owing to the highest R². The maximum biosorption capacity of CPZiONp-composite was found to be 200 mg g^-1. The biosorption data were fitted in to different kinetic models and the outcomes suggesting that pseudo second order is a satisfactory model to interpret the biosorption data owing to the highest R². Thermodynamic parameters for instance entropy, enthalpy and Gibbs free energy were computed and revealed that biosorption of metribuzin onto CPZiONp-composite is spontaneous and exothermic process.

Revisiting the Synthesis of Betti Bases: Facile, One-pot, and Efficient Synthesis of Betti Bases Promoted by FeCl3•6H2O

BACKGROUND

Betti bases are pharmaceutically and synthetically important scaffolds due to their diverse range of biological activities and applications in key synthetic transformations in organic synthesis.

OBJECTIVE

This work has been sought to contribute to the development, design, and implementation of an improved green methodology with higher atom economy and lower E-factor values for the synthesis of Betti bases.

METHOD

To realize our objectives, we screened out different catalysts and reaction conditions using one-pot multicomponent modified Mannich reaction/Betti reaction by employing 2-naphthol, benzaldehyde and pyrrolidine as model substrates.

RESULTS

The developed methodology afforded functionalized Betti bases via FeCl3•6H2O catalyzed one-pot multicomponent Betti reaction under neat conditions at 110 °C (5-15 min) to afford functionalized Betti bases by using several aromatic aldehydes and secondary amines in 60-100% yields.

CONCLUSION

A facile synthetic methodology with higher atom economy and lower E-factor values to synthesize Betti bases via FeCl3•6H2O catalyzed one-pot multicomponent Betti reaction of 2-naphthol, aromatic aldehydes, and secondary amines under neat conditions at 110 °C has been reported. The developed methodology offers various advantages such as excellent yields (60-100%), short reaction time (5-15 min), wide substrate scope (12 examples), green reaction conditions, readily available catalyst, and easy purification (without column chromatography).

Photocatalysis: an effective tool for photodegradation of dyes-a review

The disposal of dye-contaminated wastewater is a major concern around the world for which a variety of techniques are used for its treatment. The photocatalytic treatment of dye-contaminated wastewater is one of the treatment methods. Semiconductor-assisted photocatalytic treatment of dye-contaminated wastewater has gained pronounced attention recently. This review outlines the recent advancements in the photocatalytic treatment of dye-contaminated wastewater. The photocatalytic degradation of dyes follows three types of mechanisms: (1) dye sensitization through charge injection, (2) indirect dye degradation through oxidation/reduction, and (3) direct photolysis of dye. Several experimental parameters like initial concentration of dyes, pH, and catalyst dosage significantly affect the photocatalytic degradation of dyes. The photocatalytic materials can be categorized into three generations. The single-component (e.g., ZnO, TiO₂) and multiple component semiconductor metal oxides (e.g., ZnO-TiO₂, Bi₂O₃-ZnO) are categorized as first-generation and second-generation photocatalysts, respectively. The photocatalysts dispersed on an inert solid substrate (e.g., Ag-Al₂O₃, ZnO-C) are classified as third-generation photocatalysts. Finally, we reviewed the challenges that affect the photocatalytic degradation of dyes.

Mechanisms of halosulfuron methyl pesticide biosorption onto neem seeds powder

The current investigation was designed to remove halosulfuron methyl from aqueous media by means of neem seed powder (NSP) in batch modes. Characterizations of NSP were carried out by using EDX, SEM, FTIR, point of zero charge and surface analysis. Optimum operation conditions were scrutinized by studying the influence of different factors like solution pH, dose of NSP, contact time, initial halosulfuron methyl concentration and temperature. Result indicates the dependency of the removal of halosulfuron methyl on solution pH and maximal removal (54%) was achieved in acidic medium (i.e. pH 3.0). To identify the chemical surface of NSP, point of zero charge of NSP was determined and was found to be 6.5 which imply that the surface of NSP is positively charged below pH 6.6 and favored the anionic sorption. Kinetics of halosulfuron methyl were demonstrated well by pseudo second order due to highest R2 (0.99) owing to the nearness between experimental and calculated sorption capacities. Isotherm results imply that Langmuir was found to the principal model to explain the removal of halosulfuron methyl and maximum monolayer sorption capacity was determined to be 200 mg g-1. Thermodynamic parameters like ΔH°, ΔG° and ΔS° were calculated from van't Hoff plot and were found negative which suggest that removal of halosulfuron methyl is exothermic and spontaneous at low temperature. These outcomes insinuate that neem seed power may be a valuable, inexpensive and ecofriendly biosorbent for the removal of pesticides.

Controlling the Energy-Level Alignment of Silicon Carbide Nanocrystals by Combining Surface Chemistry with Quantum Confinement

The knowledge of band edges in nanocrystals (NCs) and quantum-confined systems is important for band alignment in technologically significant applications such as water purification, decomposition of organic compounds, water splitting, and solar cells. While the band energy diagram of bulk silicon carbides (SiCs) has been studied extensively for decades, very little is known about its evolution in SiC NCs. Moreover, the interplay between quantum confinement and surface chemistry gives rise to unusual electronic properties and remains barely understood. Here, we report for the first time the complete band energy diagram of SiC NCs synthesized such that they span the regime from strong to intermediate to weak quantum confinement. The absolute positions of the highest occupied (HOMO) and lowest unoccupied (LUMO) molecular orbitals show clear size dependence. While the HOMO level follows the expected behavior for quantum-confined electronic states, the LUMO energy shifts below the bulk conduction band minimum, which cannot be explained by a simple quantum confinement caused by the size effect. We show that this effect is a result of the interplay between quantum confinement and the formation of surface states due to partial and site-selective oxygen passivation.

The Differential Spectroscopic Investigation of Partitioning of Reactive Dyes in Micellar Media of Cationic Surfactant, Cetyl Trimethylammonium Bromide (CTAB)

This manuscript reports the solubilization of two reactive dyes viz. reactive black-5 (RB-5) and reactive black-8 (RB-8) in the micellar media of cationic surfactant, cetyl trimethylammonium bromide (CTAB) by differential UV/visible spectroscopy. Absorption spectra of said dyes in the presence of CTAB provide strong evidence about dye–surfactant interaction. In premicellar region ion association pair is formed between dye and surfactant while in post micellar region dye molecules get accommodated within the micelles. The values of critical micelle concentration (CMC) of CTAB in the presence of dyes, partition coefficient; Kx , free energy of partition, ∆Gp , binding constant, Kb and free energy of binding, ∆Gb were determined and compared for both dyes. It is, thus, concluded that RB-5 is solubilized to greater extent than RB-8 because of its incorporation in palisade layer of micelle close to micelle-water interface.

Evaluation of Sorption Mechanism of Pb (II) and Ni (II) onto Pea (Pisum sativum) Peels

The present study was carried out to know the sorption mechanism of Pb (II) and Ni (II) in aqueous solution using pea peels under the influence of sorbent dose, pH, temperature, initial metal ion concentration and contact time. SEM and FTIR were used for characterization of pea peels. The study showed that solution pH affects sorption process and the optimum pH for Pb (II) was 6.0 while for that of Ni (II) was 7.0. Pseudo-second order kinetic model was found to be the most suitable one to explain the kinetic data not only due to high value of R2 (>0.99) but also due to the closeness of the experimental sorption capacity values to that of calculated sorption capacity values of pseudo second order kinetic model. It can be seen from the results that Freundlich isotherm explains well the equilibrium data (R2>0.99). Sorption capacity of pea peels was 140.84 and 32.36 for Pb (II) and Ni (II) mg g-1 respectively. The positive value of ΔH° and negative values of ΔG° suggest that sorption of Pb (II) and Ni (II) onto pea peels is an endothermic and spontaneous process respectively.

Ultra-small photoluminescent silicon-carbide nanocrystals by atmospheric-pressure plasmas

Highly size-controllable synthesis of free-standing perfectly crystalline silicon carbide nanocrystals has been achieved for the first time through a plasma-based bottom-up process. This low-cost, scalable, ligand-free atmospheric pressure technique allows fabrication of ultra-small (down to 1.5 nm) nanocrystals with very low level of surface contamination, leading to fundamental insights into optical properties of the nanocrystals. This is also confirmed by their exceptional photoluminescence emission yield enhanced by more than 5 times by reducing the nanocrystals sizes in the range of 1-5 nm, which is attributed to quantum confinement in ultra-small nanocrystals. This method is potentially scalable and readily extendable to a wide range of other classes of materials. Moreover, this ligand-free process can produce colloidal nanocrystals by direct deposition into liquid, onto biological materials or onto the substrate of choice to form nanocrystal films. Our simple but efficient approach based on non-equilibrium plasma environment is a response to the need of most efficient bottom-up processes in nanosynthesis and nanotechnology.

Direct growth of polyaniline chains from N-doped sites of carbon nanotubes

Polymer grafting from graphitic carbon materials has been pursued for several decades. Unfortunately, currently available methods mostly rely on the harsh chemical treatment of graphitic carbons which causes severe degradation of chemical structure and material properties. A straightforward growth of polyaniline chain from the nitrogen (N)-doped sites of carbon nanotubes (CNTs) is presented. N-doping sites along the CNT wall nucleate the polymerization of aniline, which generates seamless hybrids consisting of polyaniline directly grafted onto the CNT walls. The resultant materials exhibit excellent synergistic electrochemical performance, and can be employed for charge collectors of supercapacitors. This approach introduces an efficient route to hybrid systems consisting of conducting polymers directly grafted from graphitic dopant sites.

Tissue distribution of gossypol enantiomers in broilers fed various cottonseed meals

Plasma and tissue concentrations of total, (+)- and (-)-gossypol were determined in broilers fed cottonseed meals (CSM) from eight oil mills (five expander solvent, two expeller, and one direct solvent). Free gossypol in the meals ranged from 0.033 to 0.180%, and total gossypol ranged from 0.974 to 1.459%. The (+)-enantiomer of gossypol varied from 53.8 to 61.3% of total gossypol. Eight CSM diets containing 28% CSM and a soybean meal control diet were fed to 162 1-d-old male broiler chicks during a 3-wk starter period. Concentrations of free gossypol in the CSM diets ranged from 92 to 504 microg/g, and total gossypol ranged from 2,626 to 4,085 microg/g. All diets were formulated with the same concentrations of digestible lysine and methionine and were fed ad libitum. At 21 d of age, there were no significant differences in body weights, feed conversions, or mortality of birds fed the CSM diets when compared to birds fed the soybean meal diet. Concentrations of (+)- and (-)-gossypol in plasma, liver, kidney, and muscle increased linearly as the level of free gossypol increased in the diets. Liver had the highest concentration of total gossypol (71.4 to 313.6 microg/g DM) followed by kidney (9.2 to 36.3 microg/g DM), plasma (3.0 to 14.6 microg/mL), and muscle (2.1 to 9.8 microg/g DM). The proportion of (-)-gossypol was higher in plasma (26.7%) and kidney (25.6%) than in muscle (19.1%) and liver (16.0%). Performance data from this study indicate CSM can be used successfully in chick starter diets at levels up to 28% when diets are formulated on a digestible amino acid basis.

Use of expander cottonseed meal in broiler diets formulated on a digestible amino acid basis

This experiment was designed to evaluate the use of expander cottonseed meal (CSM) in broiler diets formulated on a digestible amino acid basis and to determine the tissue distribution of gossypol enantiomers and their relationship to gossypol consumption. Gossypol is an antinutritional polyphenolic pigment found in cottonseed. A total of 800 1-d-old broilers (Arbor Acres) was randomly divided into 40 groups of 20 birds each and placed in a broiler house with wood shavings litter. The CSM was included in starter and grower diets at 0, 7, 14, 21, and 28% of the diet. Diets were formulated to have similar levels of digestible methionine and lysine as the 0% CSM control diet. At 21 d of age, five birds per pen were randomly selected for the determination of gossypol enantiomers in plasma, liver, heart, and breast muscle. Tissues were again collected at 42 d of age. Results of this experiment indicated that at 21 d of age cumulative body weight and feed-to-BW ratios of birds fed CSM diets were not significantly different from the control. By 35 d of age, feed-to-BW ratios of experimental birds fed the 28% CSM diet were significantly greater than the control birds, and by 42 d, BW were lower than those of the control group. Tissue concentrations of total, (+) and (-) gossypol increased linearly as the level of CSM increased. At 42 d, liver had the most gossypol with a ratio of 87% (+) gossypol to 13% (-) gossypol. Plasma contained 73% (+) gossypol and 27% (-) gossypol. Heart contained 45% (+) gossypol and 55% (-) gossypol. Breast muscle had the least gossypol. Results of this experiment indicated that expander solvent CSM could be fed to broilers at up to 21% of the total diet if amino acid digestibility was considered.

Cottonseed with a high (+)- to (-)-gossypol enantiomer ratio favorable to broiler production

This study was designed to evaluate the relative toxicity of (+)- and (-)-gossypol enantiomers in 0-3-week-old broilers. Treatments consisted of broiler starter diets formulated with either a glandless, which did not contain gossypol, a commercial glanded [62. 2% (+)-gossypol], or a glanded moco [83.2% (+)-gossypol] crushed cottonseed (CCS) (six replicates/treatment) plus a soybean meal negative control. Glandless cottonseed was mixed with the moco cottonseed (2.4% free gossypol) so that both the commercial glanded and moco glanded cottonseeds contained equivalent concentrations of free gossypol (2.0%). The cottonseed treatments were added at 5 and 10% of the diet. Body weights and feed conversions were determined weekly. Body weights and feed-to-gain ratios of broilers fed 5 and 10% glandless CCS and 5% moco CCS were not significantly different. Broilers receiving 10% commercial glanded CCS weighed significantly less than those subjected to all other treatments. Feed-to-gain ratios were significantly higher for broilers receiving 10% commercial glanded and 10% moco CCS as compared to 5% moco and glandless CCS, 10% glandless CCS, and control. Relative liver weights of birds receiving 10% moco CCS were significantly less than those of birds receiving 10% commercial CCS. The data clearly showed that broilers fed moco CCS containing a relatively high (+)- to (-)-gossypol enantiomer ratio performed better than broilers receiving commercial CCS with a lower (+)- to (-)-gossypol enantiomer ratio.

Evaluation of sorghum ergot toxicity in broilers

Three experiments evaluated the performance of broilers fed sorghum ergot consisting of sphacelia/sclerotia of Claviceps africana present in tailings removed by conditioning of seed from grain sorghum hybrid seed production fields near Uvalde (Experiments 1 and 2) and Dumas (Experiment 3), Texas. Percentage sphacelia/sclerotia and total alkaloid content, respectively, in sorghum ergot tailings were 8% and 11.3 ppm for Uvalde and 75% and 235 ppm for Dumas. Sorghum ergot and control sorghum diets were based on the NRC (1994) requirements for starting broilers. In Experiment 1, neither growth nor feed efficiency were significantly reduced in male broilers fed sorghum ergot from hatch to 3 wk of age, but liver weights were significantly greater than those in the control. In Experiment 2, straight-run broilers were raised to 6 wk of age in floor pens using a three-phase feeding program. Sorghum ergot significantly reduced gain in 4-wk-old broilers and cumulative body weight at 5 wk. Feed conversion was significantly reduced during all three phases of feeding. In Experiment 3, control sorghum and the 75% ergot tailings were added to corn-soy basal diets at rates of 2.5, 5, and 10% by weight and fed to male broilers from hatch to 3 wk of age. Sorghum ergot did not significantly reduce growth, but, during Weeks 2 and 3, feed-to-gain ratios were higher. Neither type nor concentration of sorghum ergot significantly affected relative liver weights. We did not observe significant mortality or obvious symptoms of ergot toxicity, such as necrotic lesions of the feet or vesicular dermatitis of the comb, in any of the three experiments.

Endobrst: simple and safe is best

Minimal-access treatment for ureteropelvic junction (UPJ) obstruction is becoming increasingly complex. Is there still a place for the simple procedure of balloon dilatation? To examine the symptomatic and renographic results of patients at least 6 months after balloon disruption of an obstructed UPJ, we carried out a prospective audit of outcome as judged by DTPA renograms and clinical follow-up. The procedure has been performed on a total of 21 renal units (20 patients) with follow-up of 6 to 30 months (mean 22 months). Of these, 18 (86%) were asymptomatic at 3 months, although this success rate dropped to 17 (81%) by 6 months. Renographic split function improved in 11 renal units, and excretion improve in 14. Perioperative complications were few and associated with stent insertion. Three of the patients in whom the procedure failed went on to nephrectomy (14%); all had poor renal function (split <20%) at presentation. Although the quoted success rates are lower for endoluminal balloon rupture of stenosis treatment than open pyeloplasty, the former technique has significantly less morbidity. Our nephrectomy rate reflects our less than ideal early patient selection, and our balloon dilation technique is not recommended as a salvage procedure for patients in whom nephrectomy is inevitable. The learning curve is quick to climb, and this is a fundamentally simple procedure with medium-term results that remain encouraging.

Gender affects rats' central nervous system histaminergic responses to dietary manipulation

The histaminergic system (histamine and its H1-receptor) of the central nervous system has been implicated in control of food intake. The reported studies were designed to examine the effects of food restriction and very low (1%) protein diets on central nervous system H1-receptors in male and female rats. In a series of experiments, groups of rats were freely fed a 25% protein diet, a 1% protein diet, or fed the 25% protein diet at 4 g/100 g body weight for 14-20 d. When freely fed 25% protein diets, females had higher whole-brain H1-receptor binding than males on d 1 (female 122.36 +/- 4.53 and male 65.78 +/- 3.82 pmol/g protein; P < 0.001). Changing diets affected central H1-receptor binding in both males and females (P < 0.003). When rats were fed both restricted levels of food and 1% protein diets, the receptor binding of males increased by d 5 whereas that of females decreased by d 5 (P < 0.001). When fed 1% protein diets, females had decreased H1-receptor binding (98.4 +/- 2.38 pmol/g protein) and that in males increased to 119.81 +/- 5.09 pmol/g protein. After 15 d, females had eaten significantly more food than males: females 166 +/- 4.9 g, males 124 +/- 1.9 g (P< 0.0007). Males had a significantly greater weight loss than females: males -28.8 +/- 2.6 g, females -17.08 +/- 0.97 g (P < 0.0007). When fed restricted diets, females had decreased H1-receptor binding (93.81 +/- 5.58 pmol/g) whereas binding in males increased to 111.27 +/- 8.55 pmol/g. Preliminary saturation binding studies indicated that restricted food intake lowered receptor density (females consuming 25% protein: 715 +/- 30 pmol/g protein; female restricted: 467 +/- 28 pmol/g protein, P < 0.05), while 1% protein increased receptor sensitivity, i.e., lowered KD (males consuming 25% protein: 15.3 +/- 1.8 nmol; males fed low protein: 2.8 +/- 0.27 nmol). This study suggests that dietary manipulation affects central H1-receptor binding in a gender-specific manner, thereby modulating central histaminergic activity during food or protein deficit.

Food intake is inversely correlated with central nervous system histamine receptor (H1) concentrations in male Sprague-Dawley rats fed normal, low protein, low energy or poor quality protein diets

The reported studies were designed to examine relationships between whole-brain histamine receptors (H1) and food intake in male Sprague-Dawley rats. Three different experiments were conducted. In each experiment, control rats were fed normal protein (25 g casein/100 g food) and normal metabolizable energy (16.21 kJ/100 g food) diets. Feeding low protein diets (1 g casein/100 g food) elevated central H1 receptor concentrations (P < 0.0027) and reduced voluntary food intake (P < 0.007) compared with normal diets. Feeding low energy diets lowered H1 receptor concentrations (P < 0.0089) and increased voluntary food intake (P < 0.0012). Low quality protein diets also affected the central nervous histaminergic system. Whole-brain H1 receptor concentrations were significantly higher for rats fed low quality protein (25 g gelatin/100 g food) compared with rats fed casein (P < 0.0001). Rats fed medium quality protein (25 g wheat gluten/100 g food) or low quality protein ate significantly less food (P < 0.0001). In all experiments, dietary manipulation affected central histamine receptors. Elevated concentrations of H1 receptors were associated with a decrease in food intake whereas lowered concentrations of H1 receptors were associated with an increase in food intake (P < 0.001). The results of these experiments support the hypothesis that central histamine H1 receptor concentrations in male rats are inversely correlated with voluntary food intake and affected by dietary composition.

Time course evaluation of carotenoid and retinol concentrations in posthatch chick tissue

Carotenoid and retinol concentrations were determined in chicks hatched from carotenoid-enriched eggs while being fed a carotenoid free starter diet. Single Comb White Leghorn (SCWL) hatching eggs were obtained from breeder hens fed diets enriched with either 0.2% beta-carotene, canthaxanthin, lutein, or basal control. Twenty-five day-old chicks hatched from each treatment group were placed in a battery and fed a carotenoid-free basal diet. At 1, 4, 7, 10, and 13 d, five chicks per treatment were randomly selected, and blood serum, liver, and unabsorbed yolk sac were collected for carotenoid and retinol analysis. There were no significant differences in retinol concentrations in the serum, liver, and unabsorbed yolk sac of the chickens. Only small amounts of beta-carotene were detected in the chick tissues. Concentration of all three carotenoids and retinol were greater in the liver and unabsorbed yolk sac than in serum. In the serum and liver, respective carotenoid concentrations decreased and retinol concentration increased with increasing age, whereas respective carotenoid and retinol concentrations in the unabsorbed yolk sac increased over time. It may be concluded that yolk sac carotenoids are not absorbed well, as unabsorbed yolk sac concentrations increased over time, and that carotenoid in serum and liver decrease linearly with increasing age.

Effect of beta-carotene, canthaxanthin, lutein, and vitamin E on neonatal immunity of chicks when supplemented in the broiler breeder diets

The study was designed to assess neonatal immunity of chicks hatched from breeders fed diets supplemented with beta-carotene, canthaxanthin, lutein, or vitamin E. Broiler breeder birds were fed experimental diets consisting of control, 0.04% beta-carotene, 0.04% canthaxanthin, 0.04% lutein, 0.03% alpha-tocopherol acetate, or 0.04% beta-carotene plus 0.03% alpha-tocopherol acetate. Three weeks after initiation of experimental feeding, birds were vaccinated against Newcastle disease virus. Chicks hatched from the eggs of these breeders were used to determine the neonatal immune responses. There were no significant differences in weight gain and antibody titers of 3-wk-old chicks. 3H-Thymidine uptake by bursal lymphocytes when stimulated with tetrahydrofuran was significantly higher for the chicks hatched from breeders fed diets supplemented with vitamin E, or vitamin E plus beta-carotene, than in controls. 3H-Thymidine uptake by splenic lymphocytes when stimulated with concanavalin A and phorbol 12-myristate 13 acetate was significantly higher for the chicks hatched from breeders fed diets supplemented with vitamin E or beta-carotene alone, or vitamin E plus beta-carotene, than for the control chicks. Chicks hatched from hens supplemented with vitamin E had significantly higher antibody titers at 1 and 7 d of age than chicks from the control group. Vitamin E supplementation of breeder birds increased the immune response of their progeny.

Neonatal immune response and growth performance of chicks hatched from single comb White Leghorn breeders fed diets supplemented with beta-carotene, canthaxanthin, or lutein

Forty Single Comb White Leghorn (SCWL) hens and 8 SCWL cocks were randomly divided into four treatment groups. Each group was fed a diet containing .02% beta-carotene, canthaxanthin, lutein, or basal control. After 20 d of feeding, eggs were collected daily from each experimental group for incubation. Two different hatches were set and chicks from each hatch were used for one of two different experiments. In both experiments, 24 chicks per treatment were vaccinated against Newcastle disease virus at 1 d of age and raised for 5 wk on a basal diet. In the second experiment, birds were revaccinated at 3 wk of age. In both experiments, at the end of 5 wk birds were killed and bursa of Fabricius, liver, and spleen were collected. For both experiments, there were no differences in antibody titers, weight gain, feed conversion ratio, and relative bursa weights of chicks. However in the second experiment, birds hatched from breeders fed lutein had significantly lower relative liver weights than chicks of the other treatments, whereas birds hatched from the breeders fed beta-carotene and canthaxanthin had significantly lower spleen weights than the control. These experiments suggest that carotenoids may not be effective in increasing neonatal immune response when they supplement practical breeder diets.

Carcinoid syndrome in the absence of liver metastasis: a case report and review of literature

A patient with carcinoid tumor of the head of pancreas and carcinoid syndrome presented without liver metastasis. The patient had retroperitoneal lymphadenopathy. He had symptoms of flushing, diarrhea and abdominal pain. 5-Hydroxyindoleacetic acid (5-HIAA) was elevated. Absence of liver metastasis was documented not only by the negative computed tomography (CT) scan and liver/spleen scan, but also by autopsy. Except for carcinoid arising from ovary, testis, or bronchi, the other carcinoid tumors rarely cause carcinoid syndrome without liver metastasis. The literature was reviewed, and the findings are presented.

Transformation of polycythemia vera to Ph-positive chronic myelogenous leukemia

A patient with polycythemia vera (PV) developed chronic myelogenous leukemia (CML) 8 years after his initial presentation with erythrocytosis. The patient received a total of 3.5-7 g of chlorambucil over an approximate period of 5 years. Transformation of PV to CML is very unusual; only three substantiated cases had been reported in literature until 1975, and none has been described since then. All patients received either 32P or chemotherapy for PV treatment, suggesting that irradiation and alkylating agents may have played a role in the transformation to CML.

1,25-Dihydroxyvitamin D3 (calcitriol) suppresses concanavalin A-stimulated human T cell proliferation through monocytes

1,25-Dihydroxyvitamin D3 (calcitriol) inhibits mitogen-stimulated T cell proliferation by blocking the production of interleukin 2 (IL-2). The present study was initiated to determine the role of monocytes (Mo) in this process. Either Mo or T cells were preincubated with calcitriol for 24 or 48 hr and were thoroughly washed prior to concanavalin A (Con A)-stimulated coculture period. The inhibitory effect of calcitriol was Mo mediated; pretreatment of Mo resulted in inhibition of T cell proliferation, whereas pretreatment of T cells lacked the suppressive effect. Similar results were obtained by using 7- to 20-day-old IL-2-dependent human cultured T cells instead of fresh T cells. Calcitriol did not diminish the IL-1 secretion or intracellular IL-1 production of fresh Mo and actually increased the secretion of 24-hr-old Mo. Furthermore, addition of recombinant IL-1 to Mo-T cell coculture failed to reconstitute proliferative defect. Thus, these experiments clearly demonstrate that the suppression of Con A-driven T cell proliferation by calcitriol is Mo mediated and works by a non-IL-1 mechanism. At least, under these experimental conditions of Con A-driven T cell proliferation in which Mo play an obligatory role, antiproliferative action of calcitriol is Mo dependent.

Failure of hydrocortisone to suppress the interferon-gamma-induced augmentation of interleukin 1 secretion of aged human monocytes

The combined effect of hydrocortisone (HC) and interferon-gamma and -alpha (IFN-gamma and -alpha) on human blood monocytes (Mo) interleukin 1 (IL 1) secretion was investigated. IL 1 was generated by treating the fresh or aged Mo with lipopolysaccharide (LPS), and quantitated by radioimmunoassay (RIA). Hydrocortisone, at the pharmacological attainable concentration of 10(-5) molar (M), markedly suppressed fresh Mo IL 1 secretion but had no effect at lower tested doses. Addition of IFN-gamma enhanced the IL 1 secretion of fresh Mo; however, the simultaneous addition of 10(-5) M HC and IFN-gamma resulted in marked suppression of the monokine release. Monocytes, when cultured in vitro for three days, lost the capacity to secrete IL 1. The loss of IL 1 secretory potential of aged Mo was prevented by preincubating them with IFN-gamma prior to LPS stimulation. IFN-alpha was ineffective in this regard. Aged Mo, pretreated with the combination of IFN-gamma and HC were still able to secrete abundant quantities of IL 1, demonstrating the failure of HC to suppress the IFN-gamma-induced augmentation of IL 1 secretory potential. Even suprapharmacologic doses of HC (10(-4) M) did not inhibit this enhancement and actually further augmented it. Thus, therapeutic concentrations of HC suppress IL 1 secretion of fresh Mo even in the presence of IFN-gamma; however, therapeutic or suprapharmacologic concentrations of HC do not inhibit the IL 1 secretory capacity of IFN-gamma-treated aged Mo.

Local peritoneal factors: their role in infertility associated with endometriosis

In order to detect peritoneal abnormalities that could account for infertility associated with endometriosis, 122 infertile individuals were studied at the time of laparoscopy for diagnostic purposes or for in vitro fertilization. Four groups were defined: group 1, laparoscopy without endometriosis; group 2, laparoscopy with endometriosis; group 3, in vitro fertilization without endometriosis; and group 4, in vitro fertilization with endometriosis. Mean peritoneal fluid volume was greater, although not significantly so, in group 4 (29.0 +/- 6.6 ml, mean +/- SEM) than in group 3 (18.2 +/- 2 ml). The concentration and total number of pelvic macrophages were similar for groups 1 and 2. The total number of pelvic macrophages was increased in group 4 (16.9 +/- 4.2 x 10(6)) versus group 3 (10.0 +/- 1.8 x 10(6)) (p = 0.08). The mean sperm phagocytosis in vitro did not differ among the four groups studied. Interleukin 1 activity within the peritoneal fluid and the in vitro interleukin 1 production rate did not differ between individuals with and without endometriosis. Peritoneal fluid and macrophage supernatants from individuals with endometriosis were not embryotoxic when studied in an in vitro mouse embryo system.

The effect of IFN-gamma and alpha on Con-A stimulated T-cell proliferation: role of monocytes

Interferon gamma (IFN-gamma) and alpha (IFN-alpha) have been shown to influence T-cell proliferation in several systems. Since both species of IFN affect monocyte (Mo) functions, it is conceivable that these effects are mediated through Mo. In the present study, the effect of IFN-gamma and alpha on concanavalin A (Con A)-driven T-cell proliferation was investigated under suboptimal culture conditions. T-cell proliferation was augmented by IFN-gamma. The stimulatory effect of IFN-gamma was Mo mediated and required the pretreatment of Mo with IFN-gamma prior to co-culture with T-cells. Addition of IFN-gamma during co-culture or pretreatment of T-cells with IFN-gamma was ineffective in achieving augmentation. IFN-gamma induced enhanced T-cell proliferation was not due to increased interleukin-I (IL-I) production by Mo pretreated with IFN-gamma, because addition of IL-I to control Mo-T-cells co-culture failed to increase T-cell proliferation. In contrast, IFN-alpha suppressed T-cell proliferation. The inhibitory effect of IFN-alpha was not mediated through Mo and could be achieved by preincubating the T-cells with IFN-alpha. These results demonstrate opposing effects of the two species of IFN on Con A-driven T-cell proliferation. In addition, Mo play an obligatory role in IFN-gamma induced stimulation, whereas Mo-IFN-alpha interaction is not required for IFN-alpha mediated suppression of T-cell proliferation.

Invasion of paranasal sinuses by Aspergillus oryzae

A 24-year-old male patient receiving chemotherapy for acute promyelocytic leukemia developed fever, right periorbital swelling and mild right proptosis. A head scan showed opacification of the right maxillary and ethmoid sinuses with adjacent soft tissue swelling. Biopsy of the nasal mucosa demonstrated the typical septate hyphae of Aspergillus species which was later shown on culture to be Aspergillus oryzae. A. oryzae has only rarely been reported in human disease and there is confusion as to its precise identification and role. We would like to confirm the pathogenicity of A. oryzae with this uncommon presentation of aspergillosis and also emphasize the need to take adequate and multiple cultures in suspected cases so that the possibility of species identification will be maximized.

Role of IFN-gamma and alpha in IL 1 synthesis and secretion of in vitro differentiated human macrophages: a comparative study

Human blood monocytes (Mo) cultured in vitro differentiate to macrophages (Mx) and lose the capacity to secrete interleukin 1 (IL 1) in response to endotoxin (LPS). Incubation of Mo with interferon gamma or alpha (IFN-gamma or IFN-alpha) prevented this loss of IL 1 secretory potential during the first 24 h of culture. However, there were marked differences between the two interferons if culture period was extended beyond 24 h. Incubation of Mo with IFN-gamma for 48 or 72 h induced IL 1 release in response to LPS in all the donors without exception. In contrast, 48-h incubation of Mo with IFN-alpha alpha caused IL 1 secretion (in response to LPS) in only a minority of donors, while 72-h incubation resulted in very little or no IL 1 release in all the individuals tested. Moreover, only IFN-gamma had the capacity to reinduce IL 1 secretory potential in Mx which had lost the capacity to secrete IL 1 during previous culture. These and other results suggest that IFN-alpha differs from IFN-gamma in being: a less potent IL 1 inducer, ineffective in maintaining IL 1 secretory capacity of fresh Mo for more than 48-72 h, completely unable to reinduce IL 1 secretory potential in culture-derived Mx. Thus, the two species of IFN appear to have a markedly different role in IL 1 synthesis and secretion.

The effect of gamma interferon on IL-1 secretion of in vitro differentiated human macrophages

After being cultured overnight, human monocytes lose their ability to secrete interleukin-1 (IL-1) when stimulated by lipopolysaccharide (LPS). However, when these monocytes were cultured for up to 9 days with various concentrations of interferon-gamma (IFN-gamma), these cells were found to retain their ability to secrete appreciable amounts of IL-1 on LPS stimulation. However, the effect was observed only if the monocytes were exposed to the IFN before LPS stimulation and simultaneous addition of IFN and LPS to macrophages was ineffective. This effect of IFN-gamma was related to the concentration of IFN added to the cultures and was completely neutralized by a monoclonal antibody to IFN-gamma. In addition to inducing IL-1 secretion, IFN-gamma also appeared to increase the overall production of IL-1, since reinduction of IL-1 secretion was not associated with a decrease in intracellular IL-1 content. When these macrophages were initially cultured with IFN-gamma, washed, and further cultured with IFN free medium, these macrophages were found to progressively lose their capacity to secrete IL-1 in response to LPS. Conversely, when monocytes were initially cultured in medium free of IFN, washed, and then further cultured in new medium, but now containing IFN-gamma, these macrophages were found to regain their capacity to secrete IL-1. However, the amount of reinduced IL-1 secretion decreased as the length of the initial culture period without IFN increased, with less than optimal IL-1 secretion occurring if monocytes were allowed to mature for 6 days before IFN-gamma pretreatment. In summary, these studies suggest that IFN-gamma may be important in enhancing IL-1 production and secretion by maturing macrophages and tissue macrophages and consequently may play a role in regulating the accessory cell activity of these cells for a variety of immune responses in vivo.

Interleukin 1 secretion is not required for human macrophage support of T-cell proliferation

Interleukin 1 (IL-1) is a soluble factor secreted by stimulated monocytes (Mo) and animal macrophages (Mx). We have previously demonstrated that human Mo cultured in vitro for 1-6 days transform to Mx, and retain their ability to support concanavalin A (Con A)-driven T-cell proliferation. We have also shown that, paradoxically, these Mx do not secrete IL-1, when stimulated by endotoxin (LPS). In this study we examined two alternative hypotheses: T cells plus mitogen induce Mx IL-1 production, and human Mx deliver a second signal to T cells via a non-IL-1 mechanism. IL-1 was assayed in a mouse CD-1 thymocyte system without concanavalin A. Mo/Mx were cultured with T cells at low (2 X 10(4)/200 microliters) or high (1 X 10(5)/200 microliters) concentrations for 2 or 4 days, in the presence of Con A. Six hours prior to quantitation of proliferation, 50 microliters of supernatant was removed and assayed for IL-1. As expected both Mo and Mx enhanced T-cell proliferation eight- to tenfold. Mo secreted large amounts of IL-1; there was no demonstrable IL-1 activity present in supernatants from cultures containing either T cells and Mx, or Mx alone. Similar results were obtained by preincubating the cells (Mo, Mx, and T cells) with Con A for 12 hr and removing Con A prior to a 36-hr coculture. We examined the possibility that a small amount of IL-1 may be able to support Con A-stimulated T-cell proliferation and yet may not induce thymocyte proliferation. The highest dilutions of Mo supernatant (1:125) which supported T-cell proliferation also caused a fivefold increase in thymocyte proliferation. Supernatants from Mx failed to stimulate thymocyte proliferation or support Con A-driven T-cell proliferation. However, Mo and Mx lysates contain Il-1 activity. We conclude that human Mx support Con A-induced T-cell proliferation in the absence of IL-1 secretion. Mx may support T-cell proliferation by cell-bound IL-1 or by a non-IL-1 mechanism.

Detection of amoebic antibodies using fractionated antigen in TIA and IHA tests

Thin layer immunoassay (TIA) test was used to detect anti-amoebic antibodies in the sera obtained from immunized guinea pigs. A few human sera samples were also used for antibody detection. The TIA and IHA results with whole amoeba antigen and fractionated antigen preparations were compared. Both test procedures gave better results with fractionated antigen. The results in TIA were better than in IHA tests. Thin layer immunoassay technique can be conveniently used as an alternative to IHA test for the detection of anti-amoebic antibodies.

Immunization of guinea pigs against Entamoeba histolytica using glucan as an adjuvant

Beta 1-3 polyglucose or glucan, an extract of cell wall of Saccharomyces cerevisiae, has been successfully employed in this laboratory as an effective immunopotentiator in experimental studies on amoebiasis. An antigen extract from Entamoeba histolytica was combined with beta, 1-3 glucan for immunizing guinea pigs. In order to study the effectiveness of such vaccine preparations, several batches of guinea pigs were immunized with amoeba antigen alone, and in combination with various immunoadjuvants. Antigen inoculations were carried out via intraperitoneal route. Protective immune responses were obtained against amoeba antigen by using glucan as an adjuvant partner. The study showed that glucan can be safely used as an effective immune enhancer.

T-cell subset modulation of blood erythroid burst-forming unit proliferation

Peripheral blood BFU-E are primitive erythroid progenitor cells that have been reported to exhibit an absolute dependence on T-cells for proliferation in the plasma clot system. The study reported here was undertaken to define the differential effects of TS and TH lymphocytes on proliferation of BFU-E. We investigated the effect of unfractionated T-cells, TS, and TH on in vitro growth of peripheral blood BFU-E. Cell populations were negatively selected by treatment with murine monoclonal antibodies (OKT-3, OKT-4, OKT-8) and C'. Our experiments suggest that proliferation of peripheral blood BFU-E exhibits an absolute requirement for T-cells. The capacity to enhance growth of BFU-E is approximately equal between normal unfractionated T-cells and TS and TH cells. The data suggest that the TH and TS cells defined by the OKT antibodies are not critical in the modulation of erythroid proliferation.