Viable production of hydrogen and methane from polluted water using eco-friendly plasmonic Pd-TiO2 nanocomposites

Solar-to-fuel conversion is a novel clean energy approach that has gained the interest of many researchers. Solar-driven photocatalysts have become essential to providing valuable fuel gases such as methane and hydrogen. Solar energy has emerged as a renewable, abundant energy source that can efficiently drive photochemical reactions through plasmonic photocatalysis. As a capping agent, orange peel extract was used in this study in a microwave-assisted green method to incorporate titanium dioxide with distinct amounts (3, 5, and 7 wt%) from Pd-plasmonic nanoparticles (2-5 nm). The leading role for plasmonic nanoparticles made from Pd-metal is enhancing the photocatalyst's ability to capture visible light, improving its performance. X-Ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Brunauer, Emmett, and Teller (BET) surface area analysis, and UV-vis DRS analyses have investigated the obtained plasmonic photocatalysts' crystallographic, morphological, and optical characteristics. The UV-vis absorption spectra demonstrated the visible light absorption capacity attributed to the localized surface plasmonic resonance (LSPR) behavior of the newly formed nanoplasmonic photocatalysts. The generated Pd-TiO2 nanomaterials' photocatalytic activity has been examined and evaluated for combustible gas production, including the formation of CH4 and H2 from the photocatalytic degradation of Reactive Yellow 15 (RY) during a deoxygenated photoreaction in a homemade solar photobiogas reactor.

Stimulated generation of photobiogas by morphologically tuned nanostructured ZnO and ZnO/TiO2

The photocatalytic degradation (PCD) of ethanol in an inert atmosphere on catalysis was explored in a lab-scale experiment. A morphologically tuned nanostructured controlled ZnO and ZnO/TiO₂ nanocomposites were synthesized using a simple hydrothermal process under the control of several functionally capping agents marking a milestone in photocatalysis. It is possible that this could be modified to produce photobiogas out of organic dye pollution. The photocatalysts were characterized by the use of X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer, Emmett, and Teller (BET) surface area analyzer, Scanning electron microscope (SEM-EDX), and UV–Vis absorption spectroscopy. The photocatalytic activity of the ZnO and ZnO–TiO₂ composite nanostructures was evaluated for the photodegradation of the Tartrazine (Tr) dye aqueous solution. Where the composite matrix exhibits higher photocatalytic activity than pure ZnO nanomaterials as a result of the synergistic interaction between ZnO and TiO₂ particles. This is mainly due to its higher surface area than pure ZnO. Moreover, the photocatalytic activity of the tuned nanostructured materials is found to be enhanced by the effect of the capping agent and controlling the morphology. This increase is accompanied by a significant shift in surface shape and band gap energy. According to the findings, the designed morphologies of pure ZnO photocatalyst impacted the formation of photobiogas from the photocatalytic decomposition of ethanol as a model of organic pollutants in wastewater. However, when using composite ZnO/TiO₂ photocatalysts, the rate of CH₄ formation is significantly lower than when using ZnO photocatalysts alone. This may be attributed to the synergetic effect between ZnO and TiO₂ particles which leads to a remarkable reduction in the newly formed band gap energy. This may result in a fast rate of recombination between the photogenerated charge carriers (e⁻ and h⁺).

Integrated two-phase acidogenic-methanogenic treatment of municipal sludge with thermal hydrolysis

The purpose of this research was to investigate the impact of two process configurations integrating two-phase anaerobic digestion (AD) of municipal sludge with thermal hydrolysis (TH). The TH was positioned either before or after the acidogenic fermentation phase. The fermentation process was carried out under the semi-continuous flow regime with a retention time of three days. The TH was done at a temperature of 170 °C and for 30 min. Among all the tested scenarios, the TH of sludge followed by the acidogenic fermentation resulted in the highest COD solubilization ratio (39.5%) and volatile fatty acids production (6,420 ± 400 mg/L), which was 630% and 500% more than that of the raw sludge, respectively. The sequential TH/fermentation process achieved 40% higher ultimate methane yield (240 mL/g COD) than the non-pretreated (raw) sludge. Positioning TH after the fermentation process reduced the ultimate methane yield to 231 240 mL/g COD, although it was still 32% higher than that of the raw sludge. The analysis of methane production rate and biodegradation kinetics data suggested the formation of refractory intermediates during the thermal process of sludge, which reduced the overall performance rate during the first week of the AD process. It was also revealed that acidogenic fermentation of thermally-processed sludge could diminish the adverse effect of the recalcitrant compounds formed during the thermal hydrolysis on the subsequent AD process.

Novel fluorescent nano-sensor based on amino-functionalization of Eu3+:SrSnO3 for copper ion detection in food and real drink water samples

Lanthanide-doped nanoparticles exhibit unique optical properties and have been widely utilized for different sensing applications. Herein, the Eu3+:SrSnO3@APTS nanosensor was synthesized and its optical properties were analyzed using UV-Vis and photoluminescence spectroscopy. The TEM images of the synthesized nanophosphor Eu3+:SrSnO3@APTS exhibited peanut-like morphology, composed of two or more spherical nanoparticles with an average diameter ∼33 nm. Effects of environmental pH values and doping concentrations as well as amino functionalization on the structure of Eu3+:SrSnO3 were investigated. The as-synthesized optical nanosensor was used for determination of copper ions based on a fluorescence quenching approach. Red emission with a long lifetime was obtained in the case of the 0.06 mol Eu3+:SrSnO3@APTS sample. Under the optimal experimental conditions, a Stern-Volmer plot exhibited a good linearity for copper ions over the concentration (0.00-10.8) × 10-11 mol L-1 with a correlation efficient of 0.996 and a limit of detection 3.4 × 10-12 mol L-1. The fluorescent sensor was dynamically quenched via a coulombic interaction mechanism between the Eu3+ (5L6) and Cu2+. The Eu3+:SrSnO3@APTS nanosensor with the optimal Eu3+ dopant concentration of 0.06 mol was applied for copper determination in food and real drink water samples with high recovery values. We believe that the developed nanosensor probe can also be used for the detection of other toxic compounds, with high selectivity and sensitivity.

Photovoltaic and spectroscopic characteristics of perovskite/TiO2 heterostructure photoanodes for improving the efficiency of dye sensitized solar cells

Perovskite-type ternary oxide nanostructured materials have gained great attention in recent years as promising materials for solar cell applications. However these ternary oxides have failed to be applied as a working electrode in DSSCs due to its poor performance and its inability to bind dye molecules to the surface. A heterostructure perovskite/TiO₂ photoactive electrodes is a new strategy to improve the photon-to-current efficiency (PCE) of DSSCs. In this paper, BaZrO₃ (BZ), BaTiO₃ (BT) and nanocomposite [1:1] molar% from BaTiO₃-BaZrO₃ perovskite nanostructured materials synthesized via sonochemical sol-gel methods, are coated on the top of the TiO₂ photoactive electrode. This heterostructured (perovskite/TiO₂) photoelectrode has been applied for improving the performance of dye-sensitized solar cells (DSSCs). The crystallographic, morphological and optical characteristics of the different prepared perovskite nanomaterials has been investigated by XRD, SEM, TEM, Raman and UV-Vis Diffuse reflectance spectroscopic analysis, respectively. Dye-sensitized solar cells based on the different heterostructure perovskite/TiO₂ electrodes are assembled, and high conversion efficiency (η) are calculated from the current density-voltage (J-V) characteristics of the solar cells. The results show an efficiency enhancement with about ∼22%, 37% and 51% in case of BZ, BTZ and BT respectively. These enhancements is attributed to high refractive index of the perovskite nanoparticles, higher incident photon-to-current conversion yield which is due to greater fraction of light scattered, as well as the less recombination of the photogenerated electrons.

A comprehensive dataset on anaerobic digestion of cattle manure, source separated organics, and municipal sludge using different inoculum sources

The dataset reported in this article provides quantitative data on anaerobic digestion of cattle manure, source separated organics (SSO), primary sludge (PS), and thickened waste activated sludge (TWAS) using different inoculum sources. The discussion and interpretation of the data are provided in another publication entitled “Comparison of liquid and dewatered digestate as inoculum for anaerobic digestion of organic solid wastes” [1]. The data presented in this article include 1) the gas chromatography (GC) procedure of determining the biogas composition, 2) the procedure of converting the daily biogas/methane production data from the experimental condition (mesophilic temperature of 38 °C and room pressure) to the standard temperature (0 °C) and pressure (1 atm) condition, 3) the specific methanogenic activity data, and 4) the methane daily production rate data, and 5) the organics biodegradation kinetic rates.

Comparison of liquid and dewatered digestate as inoculum for anaerobic digestion of organic solid wastes

In this study, the application of liquid and dewatered digestate was compared for the inoculation of the anaerobic digestion (AD) process. In addition to the specific methanogenic activity and biohydrogen potential tests, biochemical methane potential assay was also conducted using four different types of municipal and industrial waste streams (primary sludge, thickened waste activated sludge, source separated organics, and cattle manure). The specific methanogenic activity of the digestate cake (5.0 ± 0.5 mL-CH₄/g-VSS.d) was higher than that of the liquid digestate (3.4 ± 0.2 mL-CH₄/g-VSS.d) for the food to microorganism ratio of 0.5. The BMP results also revealed that regardless of the type of the substrate used, the application of the digestate cake as inoculum achieved statistically significantly higher methane production rate compared to the utilization of liquid digestate, most likely due to the lower concentration of dissolved contents (i.e., ammonia, soluble organic matter, heavy metals, etc.) in the diluted digestate cake. Despite the increased process rate, no statistically significant effect of the type of the inoculum was observed on the ultimate methane yield. The biohydrogen potential test revealed the similar performance of the digestate- and digestate cake-inoculated digesters in terms of biohydrogen and volatile fatty acids production. The findings of this study suggest that the digestate cake can be used as an effective alternative to the liquid digestate for the inoculation of full-scale anaerobic digesters, reducing the transportation volume by up to 90%.

Bioenergy production data from anaerobic digestion of thermally hydrolyzed organic fraction of municipal solid waste

The presented dataset in this data article provides quantitative data on the production of bioenergy (biogas and biomethane) from mesophilic batch anaerobic digestion (AD) of thermally hydrolyzed organic fraction of municipal solid waste (OFMSW). The discussion and interpretation of the data are provided in another publication entitled “Hydrothermal Pretreatment of Source Separated Organics for Enhanced Solubilization and Biomethane Recovery” (Razavi et al., 2019). The data and information presented in the current data article include (1) the ratio of soluble to particulate chemical oxygen demand (COD) under different thermal hydrolysis condition, (2) the daily measured biogas and biomethane data, (3) the cumulative methane yield data in terms of mL CH₄ produced per gram of volatile suspended solids (VSS) as well as feedstock added, (4) the ultimate methane yield data as well as the relative improvement in methane recovery compared to the control (non-hydrolyzed) digester, (5) the data of first-order organics biodegradation rate constants, (6) the procedure of measuring biogas composition via gas chromatography, (7) the procedure of converting the biogas/methane volume data acquired under the actual experimental condition (mesophilic temperature of 38 °C and atmospheric pressure) to the standard temperature (0 °C) and pressure (1 atm) condition, and (8) the procedure of determining the first-order kinetic rate constants.

Hydrothermal pretreatment of source separated organics for enhanced solubilization and biomethane recovery

The objective of this research was to evaluate the effect of the hydrothermal pretreatment on the solubilization of source separated organics (SSO) as well as the biomethane recovery through the mesophilic batch anaerobic digestion process. For this purpose, the SSO was subjected to fifteen different pretreatment conditions within five different severity index (SI) values (3, 3.5, 4, 4.5, and 5). The pretreatment temperature, holding time, and pressure ranged from 150 to 240 °C, 5 to 30 min, and 476 to 3367 kPa, respectively. The highest solubilization improvement of ∼50% was achieved under the pretreatment condition of "220 °C-10 min-2323 kPa" corresponding to the SI value of 4.5. However, the maximum biomethane production yield of 280 mL/g TCOD_added and biomethane production rate of 30 mL/g TCOD_added were obtained under the less intense pretreatment conditions of "190 °C-20 min-1247 kPa" and "170 °C-30 min-786 kPa", respectively.

Prevalence and management of ovarian venous insufficiency in the presence of leg venous insufficiency

Objective: The correlation between ovarian venous insufficiency and lower limb venous insufficiency remains poorly understood. Clinically, incompetent ovarian veins in association with lower extremity varicose veins are suspected when leg varicose veins are found in atypical distributions. Such distributions include upper lateral or posterior thigh, on the buttocks, crossing the inguinal ligament, and also in the vulval or perineal regions. The aim of this study was to determine the prevalence of ovarian venous insufficiency in those with clinically suspicious varicose veins, and to assess the effectiveness of ovarian venous embolization/ligation in treating this condition.

Methods: Between June 2001 and December 2004, 424 female patients with lower limb superficial venous insufficiency were seen by a single vascular surgeon. These patients were clinically assessed, and those with atypical varicose veins were investigated with venous duplex examination and magnetic resonance imaging (MRI) venography. Patients with proven ovarian venous insufficiency were offered venography with a view to embolization or laparoscopic ligation.

Results: A total of seven patients were clinically suspected of having ovarian venous insufficiency, of which three had recurrent varicose veins (42.9%). Of these, six were confirmed on MRI venography with the left side being more affected than the right; one of them had an occluded vena cava, three were treated by embolization, and two had laparoscopic ligation.

Discussion: The prevalence of clinically detectable ovarian venous insufficiency in association with lower extremity varicose veins is in the region of 1.65%. Compared with the estimated prevalence of incidental ovarian venous insufficiency of 10–47%, this suggests that only a minority of incompetent ovarian veins will present with clinically detectable lower limb venous insufficiency. In our opinion, patients with signs suggestive of ovarian venous insufficiency in association with lower limb venous insufficiency should have their ovarian insufficiency controlled prior to embarking on limb venous surgery.

Effect of extreme pump pulse reshaping on intense terahertz emission in lithium niobate at multimilliJoule pump energies

We report on terahertz (THz) generation via optical rectification in a room-temperature lithium niobate crystal under variable pump pulse durations, ranging from 100 to 300 fs, at 800 nm center wavelength. The efficiency for the process is predicted to have an order of magnitude increase when longer duration Fourier-limited pump pulses are used. Our results confirm this increase in efficiency, and we report a record 800 nm pump energy conversion efficiency of 0.35% with a saturation at >240  fs pulse duration. While promising, our findings show a series of key problems that must be overcome before the theoretical limit can be achieved, including the influence of the pump bandwidth broadening due to the cascaded nonlinearity taking place within the crystal.

Synthesis of highly active thin film based on TiO2 nanomaterial for self-cleaning application

Highly active self-cleaning surfaces were prepared from hydrothermally treated TiO2 nanomaterials for different times (0, 12, 24 and 36 h) under acidic condition. TiO2 thin films were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and scanning electron microscope (SEM). TiO2 thin film (hydrothermal 24h) exhibited hybrid morphology from accumulated plates, clusters, rods and spheres. The photo self-cleaning activity in term of quantitative determination of the active oxidative species (OH) produced on the thin film surfaces was evaluated using fluorescent probe method. The results show that, the highly active thin film is the hydrothermally treated for 24 h at 200 °C. The structural, morphology and photoactivity properties of nano-TiO2 thin films make it promising surfaces for self-cleaning application. Mineralization of commercial textile dye (Remazol Red RB-133, RR) from highly active TiO2 thin film surface was applied. Moreover, the durability of this nano-TiO2 thin film (hydrothermal 24h) was studied.

Photo-induced self-cleaning and sterilizing activity of Sm3+ doped ZnO nanomaterials

Highly active samarium doped zinc oxide self-cleaning and biocidal surfaces (x mol% Sm(3+)/ZnO where x=0, 1, 2 and 4 mol%) with crystalline porous structures were synthesized by hydrothermal method. Sm(3+)/ZnO thin films were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), energy dispersive spectroscopic (EDS), UV-visible diffuse reflectance and fluorescence (FL) spectroscopy. The combination between doping and hydrothermal treatments significantly altered the morphology of ZnO into rod and plate-like nanoshapes structure and enhanced its absorption and emission of ultraviolet radiation. The photo-activity in term of quantitative determination of the active oxidative species (()OH) produced on the thin film surfaces was evaluated using fluorescent probe method. The results showed that, the hydrothermally treated 2.0 mol% Sm(3+)/ZnO film (S2) is the highly active one. The optical, structural, morphology and photo-activity properties of the highly active thin film (S2) make it promising surface for self-cleaning and sterilizing applications.

Carrier density dependence of the nonlinear absorption of intense THz radiation in GaAs

We study the carrier density dependence of nonlinear terahertz (THz) absorption due to field-induced intervalley scattering in photoexcited GaAs using the optical-pump/THz-probe technique. The intervalley scattering in GaAs is strongly dependent on the photo-carrier density. As the carrier density is increased from 1 × 10(17) to 4.7 × 10(17) cm(-3), the nonlinear absorption bleaching increases. However, if the carrier density is increased further above 4.7 × 10(17) cm(-3), the trend reverses and the bleaching is reduced. The initial increase in absorption bleaching is because, unlike low THz field, high THz field experiences intervalley scattering and nonparabolicity of the conduction band. On the other hand, a simple electron transport model shows that the reduction in intervalley scattering is mainly due to the increase in the electron-hole scattering rate with the increase in the carrier density. This increase in the electron-hole scattering rate limits the maximum kinetic energy attainable by the electrons and thus reduces the observed nonlinear absorption.

Ultrasound-guided foam sclerotherapy within a rolling treatment programme is an effective low-cost treatment for superficial venous insufficiency

AIMS

To review the results and cost of a rolling ultrasound-guided foam sclerotherapy (UGFS) treatment programme for patients with chronic superficial venous insufficiency.

METHOD

A prospective study of a rolling treatment programme where patients were offered unlimited follow-up at intervals of 6-8 weeks and further (top up) UGFS when necessary, until occlusion criteria were met.

RESULTS

A total of 213 lower limbs with complete follow-up were included in the study. Median (range) age was 57 (16-94) years, maximum diameter of varicose vein was 10 (3-18) mm, C of CEAP (clinical, aetiological, anatomical and pathological elements) was 4 (2-6), number of treatment sessions was one (1-4) and follow-up was three (1.5-33) months. Satisfactory occlusion could not be achieved in nine (4%) limbs. The ratio of odds (95% CI) for requiring more than one treatment session was 3.58 (1.46-8.77), P = 0.002 for great saphenous varicosity and 2.11 (1.13-3.94), P = 0.015 for age 50 or more. There were 20 (9.3%) immediate and 63 (29.5%) delayed adverse effects. All were minor except for one cutaneous nerve injury, one pulmonary embolism and one infected haematoma. The ratio for odds (95% CI) for post-treatment skin discolouration was 2.59 (1.14-5.87), P = 0.017 for women and 1.32 (1.02-1.71), P = 0.032 for increasing sclerosant volume used. Service line costing per completed treatment episode was £115.22 (€130.07, $188.60).

CONCLUSION

UGFS in a rolling treatment programme is safe and can achieve high occlusion rates at a low cost. Patients above the age of 50 with great saphenous varicosity are likely to require more than one treatment session.

Comparison between killed and living probiotic usage versus placebo for the prevention of necrotizing enterocolitis and sepsis in neonates

The aim of the study is to compare the role of killed (KP) Lactobacillus acidophilus with living (LP) in reducing incidence of sepsis (NS) and necrotizing enterocolitis (NEC) in neonates. Randomized double blind placebo study, included 150 neonates admitted to NICU at day 1, sixty received oral (LP) and 60 received (KP) and 30 received placebo. One gram of stools was collected on admission, at day 7, at end of the study, as well as on suspected NEC or NS and was sent for culture.

RESULTS

LP and KP were preventive factors for NEC with absolute risk reduction (AAR) 16, 15%, respectively and 18% for NS compared to placebo. Incidence of NEC and NS did not differ significantly between neonates supplemented with LP and those with KP. Preterm neonates supplemented with KP showed significantly lower incidence of NEC compared to placebo, while incidence of NS showed no significant difference between both groups. There is significant reduction in NS and NEC among neonates with positive Lactobacillus colonization of gut compared to those none colonized at day 7 (27.9 vs. 85.9%, 0 vs. 7.8%) and at day 14 (48.7 vs. 91.7% for NS and 0 vs. 20.8% for NEC). Overall comparison between the three groups showed statistical significant reduction in the incidence of NEC. Present conclusions are that early gut colonization with beneficial bacteria lowers the incidence of NEC and NS. KP retained similar benefits to live bacteria.

Growth rates of small abdominal aortic aneurysms correlate with clinical events

Background

This retrospective analysis of prospectively collected abdominal aortic aneurysm (AAA) screening data aimed to identify predictors of AAA-related events (surgery or death) with a view to better targeting of screening.

Methods

For the interval 1984–2007, data for 1649 subjects with an AAA were collected prospectively as part of the Chichester AAA screening programme. This included serial aortic size measurements, blood pressure, risk factors for arterial disease and concurrent medications. AAA growth rates were adjusted for risk factor confounders using flexible hierarchical modelling. AAA growth distribution was analysed using Silverman's test of multimodality.

Results

Some 1231 subjects met the inclusion criteria of having more than one scan and a surveillance interval of over 3 months. AAA growth showed a bimodal pattern with nearly 50 per cent of all aneurysms never progressing to surgery or rupture. Adjusted annual AAA growth rates of at least 2 mm significantly predicted AAA-related events.

Conclusion

This analysis identified a bimodal growth pattern for AAA, with a significant association between annual AAA growth rate of at least 2 mm and AAA-related events.

Advantage of a one-stop referral and management service for ruptured abdominal aortic aneurysms

Background

In 2005, 4003 deaths in England and Wales were attributed to ruptured abdominal aortic aneurysm (RAAA). This study examined the referral and management patterns of this condition within one English county.

Methods

West Sussex has a population of 811 000 and is served by five hospitals with two main vascular networks. Between January 2005 and December 2007, data for community and in-hospital RAAA interventions and deaths were obtained. Probability of intervention and outcome for each network were calculated.

Results

Of 341 RAAA, 228 (66·9 per cent) presented to hospital. The mean distance travelled to hospitals with a full on-site vascular service was 17·6 (95 per cent confidence interval 15·5 to 19·7) km (124 patients) compared with 11·0 (9·5 to 12·7) km (104 patients) to hospitals with a partial or no vascular service (P < 0·001). Patients managed by the network with a one-stop RAAA management policy had an odds ratio of 2·4 for undergoing surgery and 2·5 for surviving the operation (P = 0·001 and P = 0·017 respectively).

Conclusion

Patients with RAAA should be offered a one-stop emergency vascular service even if this involves further travel. Such a strategy offers significantly higher chance of intervention and survival from ruptured AAA.

Lower extremity arterial injury: results of 550 cases and review of risk factors associated with limb loss

Background

The authors' experience of lower limb arterial injury (LLAI) management was analysed and risk factors associated with limb loss were identified.

Methods

Between 1987 and 1997, data on 550 patients with 646 LLAIs were analysed retrospectively.

Results

The mechanism of LLAI was gunshot wounds in 46 per cent, blunt trauma in 19 per cent, stabbing in 12 per cent and shotgun in 9 per cent. The most frequently injured vessel was the superficial femoral artery (37 per cent) followed by the popliteal (31 per cent), crural (11 per cent), common femoral (9 per cent) and profunda (59 per cent) arteries. In 3 per cent of patients there was a combined injury on either side of the knee. Associated injuries included bony injury in 35 per cent, nerve injury in 8 per cent and remote injuries affecting the head, chest or abdomen in 4 per cent. Surgery was carried out in 96 per cent of patients with a limb salvage rate of 84 per cent and a survival rate of 98 per cent. Despite a rising trend in LLAI, total and delayed amputation rates remained stable. On stepwise logistic regression analysis, significant (P < 0·01) independent risk factors for amputation were blocked graft (odds ratio (OR) 16·7), combined above- and below-knee injury (OR 4·4), tense compartment at presentation (OR 4·2), arterial transection (OR 2·8) and associated compound fractures (OR 2·7). Factors such as simple fractures, venous injury/ligation and the use of synthetic grafts were not associated with increased risk of limb loss.

Conclusion

LLAI carries a high amputation rate. Stab injuries are the least likely to lead to amputation whereas injuries associated with severe soft tissue damage, such as high-velocity firearm injuries and blunt trauma with compound fractures, are the most likely to do so. The most significant independent risk factor for limb loss was failed revascularization.

Mortality rates from ruptured abdominal aortic aneurysms in England

Background

Over the past 10 years significant advances have been made in understanding the natural history and pathophysiology of aortic aneurysm disease. Despite a rapid improvement in alternative repair techniques, surgery for abdominal aortic aneurysm (AAA) remains the standard method of treatment. The aim of this study was to evaluate the efficacy of this treatment at a national level.

Methods

Data for elective and emergency AAA procedures performed in England between 1989 and 1998 were obtained from the Department of Health Hospital Episode Statistics. Data for deaths secondary to ruptured and non-ruptured AAA in England for the same period were obtained from the Office of National Statistics. All figures represent age-adjusted incidence per 100 000 population.

Results

The rise in elective and emergency AAA repair rates affected mainly men rather than women. The rise in death rates from ruptured AAA was 30·3 per cent in women and 2·0 per cent in men.

Conclusion

Despite a considerable increase in elective AAA repair procedures in England, deaths from ruptured AAA continue to rise. These findings highlight the need for an efficient national strategy for improving the outcome of patients with AAA.

Shark Attack: Review of 86 Consecutive Cases

BACKGROUND

On average there are approximately 50 confirmed shark attacks worldwide annually. Despite their rarity, such incidents often generate much public and media attention.

METHODS

The injuries of 86 consecutive victims of shark attack were reviewed from 1980 to 1999. Clinical data retrieved from the South African Shark Attack Files, maintained by the Natal Sharks Board, were retrospectively analyzed to determine the nature, treatment, and outcome of injuries.

RESULTS

The majority of victims (n = 68 [81%]) had relatively minor injuries that required simple primary suture. Those patients (n = 16 [19%]) with more extensive limb lacerations longer than 20 cm or with soft-tissue loss of more than one myofascial compartment were associated with higher morbidity and limb loss. In 8 of the 10 fatalities, death occurred as a result of exsanguinating hemorrhage from a limb vascular injury.

CONCLUSION

Victims of shark attack usually sustain only minor injuries. In more serious cases, particularly if associated with a major vascular injury, hemorrhage control and early resuscitation are of utmost importance during the initial management if these patients are to survive.

Prevalence and distribution of incompetent perforating veins in chronic venous insufficiency

PURPOSE

The purpose of this study was the investigation of the prevalence and distribution of incompetent perforating veins (IPVs) in patients with different classes of chronic venous insufficiency (CVI) as defined by the updated clinical, etiologic, anatomic, and pathologic classification (CEAP) in relation to the pattern and the extent of venous reflux.

MATERIAL AND METHODS

The study included 468 limbs of 330 subjects who ranged in age from 18 to 101 years (median, 49 years). The investigation entailed a medical history, a clinical examination, and color flow duplex imaging of the lower limb veins, which were performed by the same vascular surgeon operator. The patients were classified into 7 clinical classes according to CEAP. The superficial and deep venous systems were scanned, with an emphasis on the detection of IPVs. Venous reflux was considered abnormal when its duration exceeded 0.5 seconds. IPVs were classified as medial, posterior, and anterolateral in the upper, middle, or lower third of the thigh or calf (9 thigh and 9 calf fields).

RESULTS

The IPVs were found mainly in the medial aspect, more frequently in the middle third of calf, followed by the lower calf and the middle thigh. IPVs were rare in the lateral aspect of the thigh, the medial upper and posterior lower thigh and the posterior upper and lower calf. The prevalence of the IPVs and of deep vein incompetence increased significantly with the clinical severity of CVI (r =.95, P <.01, and r =.9, P <.01, respectively). In the limbs with a documented perforating vein (PV) incompetence, the ratios of calf-to-thigh IPVs and of superficial-and-deep (S + D) over superficial-alone (S; [S + D]/S] venous incompetence increase significantly (r =.87, P <.01 and r =.9, P <.01, respectively) with CEAP grade. The prevalence of reflux involving all systems (S + D + PV) increases significantly (r =.9, P <.01) with clinical severity. In legs with CVI of CEAP 2 to 6, reflux was invariably proximal (thigh) and distal (below knee).

CONCLUSION

In CVI, IPVs are located predominately in the medial aspect of the lower extremity, more often in the middle third of the calf, followed by the lower calf and middle thigh. The prevalence of IPVs and their calf-to-thigh ratio increase linearly with the clinical severity of CVI. Both the prevalence of deep vein incompetence and the ratio of superficial and deep to superficial ([S + D]/S) increase linearly with CEAP classification. These findings support the significant relationship between deep venous reflux and PV incompetence, although the latter may exist in the absence of the former. In CEAP classes 2 to 6, reflux is invariably proximal and distal. Incompetence involving all systems (S + D + PV) increases in prevalence with the severity of CVI.

Intermittent vs maintenance medication in schizophrenia. Two-year results

This is a 2-year, double-blind, placebo-controlled study of 101 patients, evaluating the relative efficacy of intermittent medication (given only when the patient shows early signs of relapse) compared with moderate doses of maintenance medication for stable schizophrenic outpatients. Patients were dropped from the study if they had three prodromal episodes in 1 year or if an episode lasted more than 9 weeks. Fourteen percent of patients given maintenance treatment were dropped from the study compared with 46% of intermittently treated patients. Relapse rates were 16% for patients given maintenance treatment and 30% for intermittently treated patients, a nonsignificant difference. Intermittently treated patients were receiving significantly less medication, but there were no differences found in drug side effects. There appears to be no advantage in using the intermittent approach, but we found that the use of an early intervention strategy reduced the relapse and rehospitalization rates for these patients.

A comparison of masking effects of haloperidol versus molindone in tardive dyskinesia

An experimental method was utilized to compare the masking effects of two neuroleptic agents--molindone and haloperidol--on 18 neuroleptic-treated schizophrenic patients exhibiting operationally defined withdrawal-exacerbated tardive dyskinesia. After a week on one of these two medications at preestablished doses equivalent to that of the pre-study neuroleptic, molindone-masked total AIMS scores by significantly less (12%) than haloperidol (27%). Similarly, during a second week when the dose of these neuroleptics was equivalent to 200% that of the pre-study dose, molindone masked the total AIMS score significantly less (23%) as compared to haloperidol (53%). Several interpretations of this finding are considered. This study demonstrates the feasibility of a method that may offer a model for understanding pharmacological differences among neuroleptic medications.

Work and mental illness. I. Toward an integration of the rehabilitation process

For centuries, philosophers and physicians have noted the beneficial impact of work for the restoration and maintenance of mental health. This paper reports the findings from a survey in which all the principal components (both providers and consumers in one catchment area) contributed data about the degree to which vocational rehabilitation was integrated into systems of care for the mentally ill. The major repetitive themes found at the interface of each participating sector were: rigidity, isolation, compensatory ad hoc operations, and narrow frames of reference. Vocational and other forms of rehabilitation were accomplished by persistent, energetic personnel inventing ingenious solutions to the roadblocks set up at system interfaces. Their problem-solving techniques pointed to ingredients that might help to integrate treatment and rehabilitation efforts. These key elements were flexibility, collaboration, data-based training, and a unified theoretical framework.

A case of trazodone-induced ventricular tachycardia

Trazodone was associated with the occurrence of life-threatening premature ventricular contractions and angina in a 45-year-old white man who had no prior cardiovascular disease. Caution in prescribing trazodone and in the cardiac monitoring of patients receiving trazodone is recommended.

The course of psychiatric disorder, III: Longitudinal principles

The authors studied 28 patients hospitalized for functional psychiatric disorder in an attempt to explore systematically the course of psychiatric disorder. Data collected over the 2-year period following discharge suggested the existence of eight longitudinal principles for understanding the course of psychiatric disorder. These principles reflect identifiable phases and some of the factors involved in a patient's remaining in one phase or moving on to a new phase. The clinical and research implications of these principles are described.

Hypokalemia-induced psychosis in a chronic schizophrenic patient

An association is documented between hypokalemia and an acute psychotic decompensation in a patient with chronic schizophrenia. The patient's symptom picture and other aspects of the clinical presentation alone were not sufficient to differentiate between hypokalemic psychosis and an exacerbation of schizophrenia. A restricted focus on a history of psychosis, ignoring the possibility of organic factors, can be misleading and dangerous to the patient.

What is deviant about deviant smooth pursuit eye movements in schizophrenia?

Smooth pursuit eye movements of schizophrenic, hospitalized nonpsychotic, and normal control subjects (18 per group) were measured in low and high target information conditions. A computer method for measuring saccade frequency and velocity was used. The results indicated that the frequency of saccades was significantly greater in both tracking conditions for schizophrenic than for hospitalized nonpsychotic or normal subjects. Consistent with our earlier finding, the reduction in saccade frequency with high information was greatest for schizophrenic subjects. The results also yielded a unique finding: the velocity of saccades within smooth pursuit records was significantly greater for schizophrenic than for hospitalized nonpsychotic or normal subjects. Greater saccade velocity was not a result of increased saccade size; there was no significant difference in the size of saccades for normal and schizophrenic subjects. Yet, the duration of saccades was significantly less for schizophrenics than for other subjects. Target information affected the frequency, duration and size, yet not the velocity of saccades emitted by all subjects. In contrast to earlier interpretations of deviant smooth pursuit eye movements in schizophrenia, the results may provide the first evidence of differences in the functioning of the saccadic eye movement systems of schizophrenic and normal subjects.

Clinical questions and "real" research

Clinical experiences and the questions they generate are a rich potential source for increased understanding of psychopathology and its treatment. Yet a chasm frequently appears to exist isolating clinical observations from the "real" research viewed as essential to developing and testing their implications. This report suggests that a concept of real research limited to large-sample elaborate studies is too narrow for optimal progress in the field. Research principles for developing a clinical intuition systematically, in the clinical context, are described. The important values as well as limitations of this kind of research are noted.