bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of middle ear immune response on the immunological state and function of the inner ear
Authors: Gloddek B. , Lamm Kerstin , Haslov K.
Published: October 2006

According to clinical experience, a causative correlation between otitis media and sensorineural hearing loss is likely. During an otitis media, inflammatory mediators should be released and diffuse through the round window membrane to cause an immune response of the inner ear.

Using 20 guinea pigs, an immunologically caused otitis media was induced. Auditory evoked potentials were registered by means of electrocochleography and electric response audiometry from day 0 to day 7. Each time, before and after starting the immune response serum, middle ear effusion and perilymph were sampled and the concentration of interleukin‐2 (IL‐2) analyzed. Decalcified temporal bones were examined immunohistochemically.

In this study, IL‐2 was found in the middle ear effusion and perilymph, and there was evidence of an immune response of the inner ear during an otitis media. Histological results were in close correlation with this event. Electrophysiological data showed conduction deafness and signs of sensorineural hearing loss with a maximum at day 3.
Spontaneous and evoked otoacoustic emissions in preterm neonates
Authors: Bonfils Pierre , Francois Martine , Avan Paul , Londero Alain , Trotoux Jacques , Narcy Philippe
Published: October 2006

Spontaneous (SOEs) and evoked otoacoustic emissions (EOEs) were recorded in a group of preterm neonates (N = 134 ears) in order to study the basic properties of SOEs and EOEs as a function of gestational age. In the study, it was found that: 1. EOEs were recorded in 93% of the tested ears; 2. SOEs were recorded in 61% of the tested ears; 3. there were no statistically significant variations of EOE amplitude with gestational age; 4. EOE spectrum did not vary with age; and 5. the two main factors influencing EOE amplitude were the SOE presence and the fast Fourier transform spectrum, especially the lower limit of the spectrum. Thus, the maturation of outer hair cell properties appears to be complete at 32 weeks of gestational age. Because a number of infants at risk for hearing loss are preterm babies, screening for EOEs, an objective, rapid, and nontraumatic technique, may prove useful in evaluating peripheral auditory dysfunction in preterm neonates.
Serologic determinants of survival in patients with head and neck cancer: Validating a clinical prediction model
Authors: Lydiatt Daniel D. , Savage Howard E. , Clayman Gary L. , Sample Dory , Schantz Stimson P. , Liu Frank J.
Published: October 2006

Quantitative measurements of serum C1q‐binding macromolecules (C1qBM) and immunoglobulin A (IgA) were done on 162 patients using previously described methodology. The measurements were compared to a previously described head and neck cancer population. Using the Cox Proportional Hazards model, the prognostic implications regarding high ClqBM and subsequent death with disease (P = .02), and regional recurrence (P = .0094) were validated, but not our previous IgA‐related prognostic implications. When both study populations were combined, ClqBM was predictive of survival in those patients treated with induction chemotherapy (P = .0001). ClqBM was not a significant predictor of survival in patients treated with surgery plus postoperative radiation therapy in either this second “test” population or in the original “training” population. The findings demonstrate the confounding influence of treatment modalities and the importance of model validation.
Implications of positive surgical margins
Authors: Jacobs John R. , Ahmad Kurshid , Casiano Roy , Schuller David E. , Scott Charles , Laramore George E. , Al‐Sarraf Muhyi
Published: October 2006

The recently concluded Head and Neck Intergroup trial tested the addition of three courses of cis‐platinum containing chemotherapy to standard treatment of surgery and postoperative radiotherapy for patients with advanced operable squamous cell carcinoma of the head and neck. Only patients with negative surgical margins were eligible for the trial. One hundred twelve patients with positive surgical margins were dropped from the trial but continued to be followed. These patients received a variety of treatments. Positive surgical margins were most often seen in nonglottic primaries and with increasing frequency as the N stage increased. Patients with positive margins who achieved a complete clinical response to subsequent treatment had a median survival of 33.8 months vs. 9.1 months for those with less than a complete clinical response. The addition of chemotherapy did not significantly alter the median survival of the positive margin patients.
Clinical staging for primary malignancies of the supraglottic larynx
Authors: Zamora Rene L. , Harvey Joseph E. , Sessions Donald G. , Spitznagel Edward L.
Published: October 2006

A study of 520 patients with primary supraglottic cancer was conducted. The tumors were staged according to the 1983 and 1988 American Joint Committee on Cancer (AJCC) T‐and N‐stage definitions. There were 293 patients with early stage (T1, T2) tumors, 227 with advanced stage (T3, T4) tumors and 428 with early nodal disease (N0, N1) in both systems. In the 1983 N‐staging, there were 44 N2 and 48 N3 lesions; in the 1988 N‐staging, there were 62 N2 and 30 N3 lesions. Cox regression analysis showed that the 1983 and 1988 T‐stage (T1 through T4) definitions successfully prognosticate for survival when patients were without neck node involvement. In contrast, when neck nodes were present, the N‐stage (N0 through N3) of the disease prognosticated survival better than T‐stage. Further analyses showed that the 1988 N‐stage definition provided a better separation between N2 and N3 lesions compared to the 1983 version. Combined‐modality treatment (surgery and radiation) significantly improved survival compared to single‐modality treatment (surgery or radiation alone) when patients were staged T4 and N0 through N3 neck disease, but not when patients advanced from T1 to T3. Comparison of treatment efficacy over the last four decades for single‐and combined‐modality treatment did not reveal statistically significant differences in survival rates in our patient population. This was consistent with cumulative results of various institutions over the last four decades. We conclude that the 1988 AJCC T‐and N‐stage definitions successfully prognosticate for T‐stage (T1 through T4) and N‐stage (N0 through N3) with better separation of N2 and N3 lesions compared to the 1983 version.
Hemipharyngectomy and hemilaryngectomy for pyriform sinus cancer: Reconstruction with remaining larynx and hypopharynx and with tracheostomy
Authors: Barzan Luigi , Comoretto Roberto
Published: October 2006

When resection of the posterior hypopharyngeal wall is undertaken for treatment of pyriform sinus carcinoma, a very narrow mucosal strip may be left for reconstruction. A surgical technique for carcinoma which has invaded the whole lateral hypopharyngeal wall is described. It consists of resecting half the larynx and half the hypopharynx and reconstructing the food canal using the mucosa of the unaffected half of the larynx and the remnant hypopharynx. A series of 34 patients treated by this technique is presented. No hypopharyngeal stenosis was observed. Local recurrences developed in 9 cases and distant metastases in 6. A specific disease mortality rate of 44% was encountered. At present, 15 patients are disease‐free after a median follow‐up of 48 months.
Otoacoustic emissions in full‐term newborns at risk for hearing loss
Authors: Lafreniere D. , Smurzynski J. , Jung M. , Leonard G. , Kim D. O.
Published: October 2006

Distortion product otoacoustic emissions (DPOEs) and click‐evoked otoacoustic emissions (CEOEs) characteristics of the normal newborn population have been previously reported in the literature. There is little information about DPOE evaluations in the newborn population at risk for hearing loss. The authors now report the DPOE and/or CEOE data from six full‐term subjects at risk for hearing loss or with highly suspected hearing loss. These subjects were less than 1 year of age and at risk for hearing loss secondary to a history of hereditary hearing loss, meningitis, hyperbilirubinemia, and ototoxic drug exposure. Audiometric evaluation included auditory brainstem responses (ABR), behavioral observation audiometry, and tympanometry. The CEOEs and DPOEs were found to be decreased or absent in the subjects with suspected hearing loss secondary to cochlear pathology; they were found to be normal in a subject with a suspected central hearing loss. This study's data suggest that otoacoustic emissions when combined with ABR can provide a frequency‐specific evaluation of cochlear function and help determine the anatomic site of a pathologic lesion.
Adenosinergic Mechanisms Contribute to Individual Differences in Sleep Deprivation-Induced Changes in Neurobehavioral Function and Brain Rhythmic Activity
Authors: Rétey Julia V. , Adam Martin , Gottselig Julie M. , Khatami Ramin , Dürr Roland , Achermann Peter , Landolt Hans-Peter
Published: October 2006

Large individual differences characterize the changes induced by sleep deprivation on neurobehavioral functions and rhythmic brain activity. To investigate adenosinergic mechanisms in these differences, we studied the effects of prolonged waking and the adenosine receptor antagonist caffeine on sustained vigilant attention and regional electroencephalogram (EEG) power in the ranges of theta activity (6.25–8.25 Hz) in waking and the slow oscillation (<1 Hz) in sleep. Activity in these frequencies is functionally related to sleep deprivation. In 12 subjectively caffeine-sensitive and 10 -insensitive young men, psychomotor vigilance task (PVT) performance and EEG were assessed at 3 h intervals before, during, and after one night without sleep. After 11 and 23 h waking, subjects received 200 mg caffeine and placebo in double-blind, cross-over manner. In the placebo condition, sleep deprivation impaired PVT speed more in caffeine-sensitive than in caffeine-insensitive men. This difference was counteracted by caffeine. Theta power in waking increased more in a frontal EEG derivation than in a posterior derivation. Caffeine attenuated this power gradient in caffeine sensitive subjects. Sleep loss also differently affected the power distribution <1 Hz in non-rapid eye movement sleep between caffeine sensitive and insensitive subjects. Also, this difference was mirrored by the action of caffeine. The effects of sleep deprivation and caffeine on sustained attention and regional EEG power in waking and sleep were inversely related. These findings suggest that adenosinergic mechanisms contribute to individual differences in waking-induced impairment of neurobehavioral performance and functional aspects of EEG topography associated with sleep deprivation.
Intracellular Zinc Elevation Measured with a “Calcium-Specific” Indicator during Ischemia and Reperfusion in Rat Hippocampus: A Question on Calcium Overload
Authors: Stork Christian J. , Li Yang V.
Published: October 2006

Much of our current evidence concerning of the role of calcium (Ca2+) as a second messenger comes from its interaction with fluorescent probes; however, many Ca2+probes also have a higher affinity for another divalent cation: zinc (Zn2+). In this study, using a selective Zn2+probe (Newport Green), we investigated the accumulation of intracellular Zn2+transients in acute rat hippocampal slices during ischemia, simulated by oxygen and glucose deprivation (OGD). Subsequent reperfusion with glucose-containing oxygenated medium resulted in an additional increase in intracellular Zn2+. Such observations compelled us to investigate the contribution of Zn2+to the alleged intracellular Ca2+overload occurring in ischemia and reperfusion. Using confocal fluorescent microscopy of Calcium Green-1, a widely used Ca2+indicator, we detected increases in fluorescence intensity during OGD and reperfusion. However, application of a Zn2+chelator, at the peak of the fluorescence elevation (interpreted as Ca2+overload), resulted in a significant drop in intensity, suggesting that rising Zn2+is the primary source of the increasing Calcium Green-1 fluorescence. Finally, staining with the cell viability indicator propidium iodide revealed that Zn2+is responsible for the ischemic neuronal cell death, because Zn2+chelation prevented cells from sustaining ischemic damage. Current cellular models of ischemic injury center on Ca2+-mediated excitotoxicity. Our results indicate that Zn2+elevation contributes to conventionally recognized Ca2+overload and also suggest that the role of Ca2+in neurotoxicity described previously using Ca2+probes may need to be re-examined to determine whether effect previously attributed to Ca2+could, in part, be attributable to Zn2+.
Dopaminergic Control of Sleep–Wake States
Authors: Dzirasa Kafui , Ribeiro Sidarta , Costa Rui , Santos Lucas M. , Lin Shih-Chieh , Grosmark Andres , Sotnikova Tatyana D. , Gainetdinov Raul R. , Caron Marc G. , Nicolelis Miguel A. L.
Published: October 2006

Dopamine depletion is involved in the pathophysiology of Parkinson's disease, whereas hyperdopaminergia may play a fundamental role in generating endophenotypes associated with schizophrenia. Sleep disturbances are known to occur in both schizophrenia and Parkinson's disease, suggesting that dopamine plays a role in regulating the sleep–wake cycle. Here, we show that novelty-exposed hyperdopaminergic mice enter a novel awake state characterized by spectral patterns of hippocampal local field potentials that resemble electrophysiological activity observed during rapid-eye-movement (REM) sleep. Treatment with haloperidol, a D2dopamine receptor antagonist, reduces this abnormal intrusion of REM-like activity during wakefulness. Conversely, mice acutely depleted of dopamine enter a different novel awake state characterized by spectral patterns of hippocampal local field potentials that resemble electrophysiological activity observed during slow-wave sleep (SWS). This dopamine-depleted state is marked by an apparent suppression of SWS and a complete suppression of REM sleep. Treatment with D2(but not D1) dopamine receptor agonists recovers REM sleep in these mice. Altogether, these results indicate that dopamine regulates the generation of sleep–wake states. We propose that psychosis and the sleep disturbances experienced by Parkinsonian patients result from dopamine-mediated disturbances of REM sleep.
Deletion of Annexin 2 Light Chain p11 in Nociceptors Causes Deficits in Somatosensory Coding and Pain Behavior
Authors: Foulkes Thomas , Nassar Mohammed A. , Lane Tim , Matthews Elizabeth A. , Baker Mark D. , Gerke Volker , Okuse Kenji , Dickenson Anthony H. , Wood John N.
Published: October 2006

The S100 family protein p11 (S100A10, annexin 2 light chain) is involved in the trafficking of the voltage-gated sodium channel NaV1.8, TWIK-related acid-sensitive K+channel (TASK-1), the ligand-gated ion channels acid-sensing ion channel 1a (ASIC1a) and transient receptor potential vanilloid 5/6 (TRPV5/V6), as well as 5-hydroxytryptamine receptor 1B (5-HT1B), a G-protein-coupled receptor. To evaluate the role of p11 in peripheral pain pathways, we generated aloxP-flanked (floxed) p11 mouse and used the Cre-loxPrecombinase system to delete p11 exclusively from nociceptive primary sensory neurons in mice. p11-null neurons showed deficits in the expression of NaV1.8, but not of annexin 2. Damage-sensing primary neurons from these animals show a reduced tetrodotoxin-resistant sodium current density, consistent with a loss of membrane-associated NaV1.8. Noxious coding in wide-dynamic-range neurons in the dorsal horn was markedly compromised. Acute pain behavior was attenuated in certain models, but no deficits in inflammatory pain were observed. A significant deficit in neuropathic pain behavior was also apparent in the conditional-null mice. These results confirm an important role for p11 in nociceptor function.
A Behavioral Role for Feature Detection by Sensory Bursts
Authors: Marsat Gary , Pollack Gerald S.
Published: October 2006

Brief episodes of high-frequency firing of sensory neurons, or bursts, occur in many systems, including mammalian auditory and visual systems, and are believed to signal the occurrence of particularly important stimulus features, i.e., to function as feature detectors. However, the behavioral relevance of sensory bursts has not been established in any system. Here, we show that bursts in an identified auditory interneuron of crickets reliably signal salient stimulus features and reliably predict behavioral responses. Our results thus demonstrate the close link between sensory bursts and behavior.
Olfactory Discrimination Learning Increases the Survival of Adult-Born Neurons in the Olfactory Bulb
Authors: Alonso Mariana , Viollet Cécile , Gabellec Marie-Madeleine , Meas-Yedid Vannary , Olivo-Marin Jean-Christophe , Lledo Pierre-Marie
Published: October 2006

In the olfactory bulb (OB), new neurons are added throughout life, forming an integral part of the functioning circuit. Yet only some of them survive more than a month. To determine whether this turnover depends on olfactory learning, we examined the survival of adult newborn cells labeled with the cell division marker BrdU, administered before learning in an olfactory discrimination task. We report that discrimination learning increases the number of newborn neurons in the adult OB by prolonging their survival. Simple exposure to the pair of olfactory cues did not alter neurogenesis, indicating that the mere activation of sensory inputs during the learning task was insufficient to alter neurogenesis. The increase in cell survival after learning was not uniformly distributed throughout angular sectors of coronal sections of the OB. Monitoring odor activation maps using patterns of Zif268 immediate early gene expression revealed that survival was greater in regions more activated by the non-reinforced odorant. We conclude that sensory activation in a learning context not only controls the total number of newborn neurons in the adult OB, but also refines their precise location. Shaping the distribution of newborn neurons by influencing their survival could optimize the olfactory information processing required for odor discrimination.
Addiction and Arousal: Alternative Roles of Hypothalamic Peptides: Figure 1.
Authors: Lecea Luis de , Jones Barbara E. , Boutrel Benjamin , Borgland Stephanie L. , Nishino Seiji , Bubser Michael , DiLeone Ralph
Published: October 2006

The importance of the lateral hypothalamus in the regulation of reward and motivation has long been recognized. However, the neuronal network involved in such a hypothalamic regulation of reward remains essentially unknown. Recently, hypocretin-containing neurons, a group of hypothalamic neurons known to be associated with the stability of arousal, have emerged as important structures in the control of brain reward function. This review summarizes a Mini-Symposium presented at the 2006 Annual Meeting of the Society for Neuroscience.
Singing Mice, Songbirds, and More: Models for FOXP2 Function and Dysfunction in Human Speech and Language
Authors: White Stephanie A. , Fisher Simon E. , Geschwind Daniel H. , Scharff Constance , Holy Timothy E.
Published: October 2006

In 2001, a point mutation in the forkhead box P2 (FOXP2) coding sequence was identified as the basis of an inherited speech and language disorder suffered by members of the family known as “KE.” This mini-symposium review focuses on recent findings and research-in-progress, primarily from five laboratories. Each aims at capitalizing on the FOXP2 discovery to build a neurobiological bridge between molecule and phenotype. Below, we describe genetic through behavioral techniques used currently to investigate FoxP2 in birds, rodents, and humans for discovery of the neural bases of vocal learning and language.
Home Management of Upper Airway Obstruction in Pierre Robin Sequence Using a Nasopharyngeal Airway
Authors: Anderson K. D. , Cole A. , Chuo C. B. , Slator R.
Published: October 2006

Objective:

This unit has reported management of infants with Pierre Robin Sequence (PRS) and upper airway obstruction using nasopharyngeal airways and nutritional support until enough growth takes place for the infant to thrive. There was a mean hospital stay of 60 days. This long in-patient stay prompted review of our management protocols and consideration of treatment at home. This paper reports our experience of managing infants with PRS at home using a nasopharyngeal airway and nasogastric feeding tube and reviews whether such management reduces in-patient stay while remaining safe and effective.

Design:

Retrospective review of cases referred over a 3.5-year period. Comparison is made with the unit's previously published results.

Patients:

Thirteen PRS infants were referred to the West Midlands Regional Cleft service and required transfer to Birmingham Children's Hospital for specialist assessment and airway control.

Interventions:

The parents of 12 infants underwent training to manage the airway and feeding tube. Treatment then continued at home.

Outcome measures:

In-patient episode, rate of weight gain, and complication rate were used.

Results:

The median hospital stay was 19.5 days compared to 54 days previously. The median rate of weight gain was 34 g/d. There were no complications or readmissions.

Conclusion:

This series demonstrates the revised management protocol followed has reduced in-patient stays and remained effective, with infants continuing to thrive after discharge home, and has a low complication rate.
Briefing: Aircrete
Authors: Fudge C. A. , Limbachiya M. C.
Published: October 2006

Aircrete, also known as autoclaved aerated concrete (AAC), was first produced in the UK in the 1950s. It is one of the lightest forms of concrete, and one of the most technically advanced materials used for the manufacture of mass-produced concrete blocks. It is manufactured in a range of densities from 400 to 800 kg/m3, making it considerably lighter than conventional aggregate concrete. Approximately 3 000 000 m3 of aircrete masonry units are now produced in the UK annually, representing about a third of all concrete masonry. The main benefit is that acoustic, energy conservation, fire resistance and structural properties are provided in one product. This briefing note explains the manufacture, design and application of aircrete masonry units. Innovative methods of construction have also been made possible as a result of modern manufacturing techniques, such as thin-layer mortar jointing and blocks with handholds in the block perpends.
Performance of helically shaped metal fasteners in timber
Authors: Coste G. , Kermani A. , Porteous A.
Published: October 2006

This paper presents an experimental investigation into the withdrawal resistance of a new connector type for use in structural timber. The structural performance of several helically shaped metal fasteners, which for some years have been used as wall ties and in masonry repairs, are investigated for use in a variety of timber connection systems. This paper describes part of a research programme investigating the withdrawal resistance and behaviour of these fasteners compared with conventional nails. It also details the effects of predrilling, density of timber, depth of penetration and timber grain orientation on the withdrawal resistance of these fasteners. The results show that helically shaped metal connectors achieve greater withdrawal resistance and exhibit a more ductile behaviour than common nails. A semi-empirical model is developed to predict the withdrawal performance of the fasteners.
Evaluating in situ shear strength of bituminous pavements
Authors: Naderi M.
Published: October 2006

The friction transfer method described in this paper can be used to estimate the in situ shear strength of bituminous pavement layers. In this method a specially devised apparatus fits on the top of the partial core and is clamped to it. A torque is applied using an ordinary torquemeter, and the maximum shear stress at failure is calculated. Comparative studies of laboratory Marshall stability and friction transfer tests produced correlation coefficients of 0·72 and 0·82 for linear and polynomial best-fit curves respectively, and the respective linear correlation coefficient for the in situ tests was found to be 0·84. The measured values for Marshall and friction transfer tests ranged from 750 to 1100 kg and from 1·2 to 1·8N/mm2 respectively. The average coefficients of variation of eight series of experiments were found to be 11·07% for Marshall stability tests and 11·39% for the friction transfer method. Based on the laboratory and site experiments, and considering such factors as versatility, simplicity, speed, applicability under any site conditions by untrained operators, very low cost, easily interpreted and understood results, and good accuracy, this new method is strongly recommended for the assessment of the in situ shear strength of bituminous materials.
Waterborne pathogens in urban watersheds
Authors: Arnone Russell D. , Perdek Walling Joyce
Published: October 2006

A serious concern for managers of water resources, pathogens in the urban environment easily enter waters through a number of pathways, including discharge of inadequately treated sewage, stormwater runoff, combined sewer overflows and sanitary sewer overflows. Pathogens in US ambient water bodies are regulated under the Clean Water Act (CWA), while pathogens in drinking water supplies are regulated under the Safe Drinking Water Act. Total maximum daily loads (TMDLs) are developed in accordance with CWA regulations for ambient water bodies with bacterial concentrations exceeding the water quality standard, which generally is a measure of a bacterial indicator organism. However, developing a TMDL for a supplementary indicator or pathogen is also required if a use impairment would still exist even after the water body is in compliance with the standard. This occurs because indicator organisms do not reflect the presence of pathogen contamination with complete certainty. The evaluation of pathogen indicators and summary of epidemiological studies presented are resources for those developing TMDLs to achieve water quality standards and restore water bodies to their intended uses.
Waterborne transmission of protozoan parasites: A worldwide review of outbreaks and lessons learnt
Authors: Karanis Panagiotis , Kourenti Christina , Smith Huw
Published: October 2006

At least 325 water-associated outbreaks of parasitic protozoan disease have been reported. North American and European outbreaks accounted for 93% of all reports and nearly two-thirds of outbreaks occurred in North America. Over 30% of all outbreaks were documented from Europe, with the UK accounting for 24% of outbreaks, worldwide. Giardia duodenalis and Cryptosporidium parvum account for the majority of outbreaks (132; 40.6% and 165; 50.8%, respectively), Entamoeba histolytica and Cyclospora cayetanensis have been the aetiological agents in nine (2.8%) and six (1.8%) outbreaks, respectively, while Toxoplasma gondii and Isospora belli have been responsible for three outbreaks each (0.9%) and Blastocystis hominis for two outbreaks (0.6%). Balantidium coli, the microsporidia, Acanthamoeba and Naegleria fowleri were responsible for one outbreak, each (0.3%). Their presence in aquatic ecosystems makes it imperative to develop prevention strategies for water and food safety. Human incidence and prevalence-based studies provide baseline data against which risk factors associated with waterborne and foodborne transmission can be identified. Standardized methods are required to maximize public health surveillance, while reporting lessons learned from outbreaks will provide better insight into the public health impact of waterborne pathogenic protozoa.
Health impact of water and sanitation infrastructure reconstruction programmes in eight Central American communities affected by Hurricane Mitch
Authors: Moll Deborah M. , McElroy Rebecca H. , Sabogal Raquel , Corrales Lana F. , Gelting Richard J.
Published: October 2006

In response to Hurricane Mitch, which struck Central America in October–November 1998, the American Red Cross (ARC) and the Centers for Disease Control and Prevention (CDC) collaborated on a 3-year evaluation of the public health impact of ARC's water, sanitation and hygiene education activities in eight study areas in Honduras, Nicaragua, El Salvador and Guatemala. The evaluation compared: 1) access to and use of water and sanitation facilities, 2) the use of hygienic behaviours, and 3) diarrhoeal prevalence in children younger than 3 years of age before (February 2000) and after (February 2002) the interventions had been implemented. The evaluation included household and key informant interviews designed to measure these three components. Water quality of community water sources and household water was evaluated by measuring levels of indicator bacteria. During the final survey, an infrastructure evaluation provided a review of the design, construction, and current operation and maintenance of the water systems and latrines. The integrated water and sanitation infrastructure interventions and hygiene education programmes implemented following Hurricane Mitch effectively decreased diarrhoea prevalence in the target communities.
Larval habitats of potential mosquito vectors of West Nile virus in the Florida Keys
Authors: Hribar Lawrence J.
Published: October 2006

The occurrence of larvae of two potential vectors of West Nile virus, Culex nigripalpus and Culex quinquefasciatus, was examined in the Florida Keys. About half of the aquatic habitats examined contained larvae of either one or both of the species. Culex quinquefasciatus was the most frequently encountered species, whereas only 9% of habitats sampled contained Culex nigripalpus. Over half of those samples that contained Culex nigripalpus also contained Culex quinquefasciatus. The two species utilize similar larval habitats in the Florida Keys, Monroe County, Florida, USA.
Enhanced sludge conditioning by enzyme pre-treatment: comparison of laboratory and pilot scale dewatering results
Authors: Dursun D. , Turkmen M. , Abu-Orf M. , Dentel S.K.
Published: October 2006

The effect of enzyme pre-treatment on dewaterability of anaerobically digested sludge was investigated at both laboratory and pilot scale. Our results revealed a significant increase in cake solid content (27% cake solids compared to 18% without enzyme pre-treatment), using an enzyme dose of only 20 mg/L. In order to assess practical application, enzyme pre-treatment was applied at the Wilmington, Delaware (US) wastewater treatment plant, using a pilot-scale centrifuge. However, the efficiency reached in laboratory scale could not be obtained in pilot scale, where the final cake solids content did not exceed 20%. Centrifuge and belt filter press (simulated by Crown Press™) dewatering were compared in terms of the process efficiencies in the absence and presence of enzyme pre-treatment. Possible factors that might cause the differences were tested by experimental and statistical comparisons. Results indicated that the higher shear applied in centrifugation is responsible for the lack of improved cake solids. The network strength of sludge determined by rheological measurements revealed that enzymatic treatment weakens the gel structure of the sludge floc through the hydrolysis of extracellular polymeric substances; this allows improved dewatering by filtration processes, but leads to floc deterioration when subjected to high shear during centrifugation.
Biological sludge solubilisation for reduction of excess sludge production in wastewater treatment process
Authors: Yamaguchi T. , Yao Y. , Kihara Y.
Published: October 2006

A novel sludge disintegration system (JFE-SD system) was developed for the reduction of excess sludge production in wastewater treatment plants. Chemical and biological treatments were applied to disintegrate excess sludge. At the first step, to enhance biological disintegration, the sludge was pretreated with alkali. At the second step, the sludge was disintegrated by biological treatment. Many kinds of sludge degrading microorganisms integrated the sludge. The efficiency of the new sludge disintegration system was confirmed in a full-scale experiment. The JFE-SD system reduced excess sludge production by approximately 50% during the experimental period. The quality of effluent was kept at quite a good level. Economic analysis revealed that this system could significantly decrease the excess sludge treatment cost.
Organic matter release in low temperature thermal treatment of biological sludge for reduction of excess sludge production
Authors: Paul E. , Camacho P. , Lefebvre D. , Ginestet P.
Published: October 2006

Thermal treatment applied in association with a biological system allows for a significant reduction in excess sludge production (∼50%). In general, heat treatment is described as a sludge disintegration technique. This paper offers a thorough study on the impact of heat treatment, at temperatures below 100 °C, on the solubilisation of the sludge COD and its biodegradability. Discontinuous heating experiments were performed on activated and digested sludge. At all temperatures tested the released COD for digested sludge was systematically higher than that for activated sludge (15 and 40%, respectively, at 95 °C for 40 min of contact time). For the first 30 min, a 1st order kinetic, with respect to the residual COD, was systematically found. In the range of 40–95 °C, digested sludge had a lower activation energy than activated sludge (26 kcal/mol compared to 70–160 kcal/mol). COD solubilisation is thus more positively influenced by temperature in the case of activated sludge. This may be due to the significant difference in the ratio of protein/carbohydrate in digested and activated sludge (1–5 and 0.2–0.7, respectively). The increase in the COD/TKN ratio in the solubilised fraction after thermal treatment of activated sludge suggests a preferential solubilisation of proteins over carbohydrates. Respirometric tests performed on the solubilised COD showed that whatever the sludge origin, only 40–50% of released COD is biodegradable at a conventional hydraulic retention time (i.e. 24 h). Hence, heat treatment would act more through organic matter solubilisation rather than by a biodegradability increase.
Effect of feed/inoculum ratio on anaerobic digestion of sonicated sludge
Authors: Braguglia C.M. , Mininni G. , Tomei M.C. , Rolle E.
Published: October 2006

In recent years, relevant interest has been devoted to activated sludge disintegration and solubilisation techniques in order to cope with the biological limitations related to particulate degradation. Mechanical disintegration with ultrasound can efficiently transform insoluble organics into a soluble form: the solubilised organic matter is released from the cells to the bulk phase, thus accelerating the hydrolysis step in the digestion process. Experiments were carried out on bench scale anaerobic reactors fed with either untreated or disintegrated excess sludge, added with a biomass inoculum taken from a full scale anaerobic digester. Digestion tests have been carried out at different feed/inoculum ratios (F/I) in the range of 0.1–2, kinetics of VS reduction has been investigated and a beneficial effect of sonication is observed for all the experimental conditions. Similar beneficial results have also been found for biogas production with a maximum gain of 25% at 0.5 F/I ratio.
Integrated chemical, physical and biological processes modelling of anaerobic digestion of sewage sludge
Authors: Sötemann S.W. , van Rensburg P. , Ristow N.E. , Wentzel M.C. , Loewenthal R.E. , Ekama G.A.
Published: October 2006

The biological kinetic processes for anaerobic digestion (AD) are integrated into a two phase subset of a three phase mixed weak acid/base chemistry kinetic model. The approach of characterising sewage sludge into carbohydrates, lipids and proteins, as is done in the International Water Association (IWA) AD model No 1 (ADM1), requires measurements that are not routinely available on sewage sludges. Instead, the sewage sludge is characterised with the COD, carbon, hydrogen, oxygen and nitrogen (CHON) composition and is formulated in mole units, based on conservation of C, N, O, H and COD. The model is calibrated and validated with data from laboratory mesophilic anaerobic digesters operating from 7 to 20 d sludge age and fed a sewage primary and humus sludge mixture. These digesters yielded COD mass balances between 107–109% and N mass balances between 91–99%, and hence the experimental data is accepted as reasonable. The sewage sludge COD is found to be 32–36% unbiodegradable (depending on the kinetic formulation selected for the hydrolysis process) and to have a C3.5H7O2N0.196 composition. For the selected hydrolysis kinetics of surface mediated reaction (Contois), with a single set of kinetic and stoichiometric constants, for all retention times good correlation is obtained between predicted and measured results for: (i) COD; (ii) free and saline ammonia (FSA); (iii) short chain fatty acids (SCFA); (iv) H2CO3* alkalinity; (v) pH of the effluent stream; (vi) CO2; and (vii) CH4 gases in the gas stream. The measured composition of primary sludge from two local wastewater treatment plants ranged between C3.38H7O1.91N0.21 and C3.91H7O2.04N0.16. The predicted composition based on mass balances is therefore within 5% of the average measured composition providing persuasive validation of the model.
Extraction efficiency of phosphate from pre-coagulated sludge with NaHS
Authors: Kato F. , Kitakoji H. , Oshita K. , Takaoka M. , Takeda N. , Matsumoto T.
Published: October 2006

The recovery of phosphorus from sewage and sludge treatment systems is particularly important because it is a limited resource and a large proportion of the phosphorus currently used in Japan must be imported. We have been experimentally evaluating recovery methods with sulphide. In this study, we focussed on the extraction of phosphate from the sludge, and sought to achieve a greater extraction efficiency and to validate the extraction mechanism. We conducted three experiments, i.e. a sludge-type experiment, a coagulant ratio of pre-coagulated sludge experiment, and a concentration of pre-coagulated sludge experiment. Phosphate was extracted not with normal sewage sludge but with pre-coagulated sludge and FePO4 reagent at S/Fe=1.0–2.0. A coagulant ratio of 23 mg Fe L−1 was required in the pre-coagulation process to effectively extract phosphate. A high concentration of pre-coagulated sludge was required for the phosphate extraction. The mass balance was calculated, and 44.0% of phosphorus was extracted to supernatant, and 98.5% of iron and 98.3% of sulphur (44.1% of sulphur was sulphide). Thus, phosphate can be selectively separated from iron by the phosphate extraction method with NaHS, and phosphorus and iron can be recovered and reused at sewage treatment plants using ferric chloride as a coagulant.
The effects of water treatment residues on soil respiration and microbial community structure
Authors: Pecku S. , Hunter C.H. , Hughes J.C.
Published: October 2006

Land disposal of water treatment residue (WTR), a by-product of potable water production, is increasingly being considered a viable alternative to land filling. It is crucial, inter alia, that soil quality is not affected adversely. Six different WTRs obtained from South African water treatment facilities were added to Hutton and Westleigh topsoils at rates of 0, 5, 15 and 25% (m/m) to determine their impacts on soil basal respiration. In general, respiration increased with rate of addition of WTR. The Umgeni, Rand, Midvaal and Faure2 WTRs had the greatest effect on respiration. Increases in respiration became less marked with time. The Hutton topsoil was mixed with the WTRs (at 15% m/m) and, following incubation, the bacterial community structure was examined by denaturing gradient gel electrophoresis. Changes in community structure were detected after 5 d and were attributed to physico-chemical changes arising from WTR amendment. However, dominant bands associated with the Hutton soil were retained and microbial diversity was not adversely affected. The findings of this investigation suggest that WTRs can be applied to the Hutton soil at a rate of at least 15% (300 Mg ha−1) without having a detrimental effect on microbial indicators of soil quality.
What Should I Know About Injectable Weight-Loss Medications?
Authors: Kraftson Andrew , Griauzde Dina
Published: March 2024

This JAMA Internal Medicine Patient Page describes how to use injectable weight-loss medications as well as their risks and benefits.
Carbon Aerogels Derived from Anion‐Modified Nanocellulose for Adaptive Supercapacitor Performance
Authors: Al Haj Yazan , Soliman Ahmed B. , Vapaavuori Jaana , Elbahri Mady
Published: March 2024

In the pursuit of developing advanced carbon aerogel (CA) supercapacitors, a rational design approach is introduced that utilizes often overlooked conjugated anions to modulate the properties of CAs. Ionic cross‐linking of cellulose nanocrystal (CNC) aerogels ensures the preservation of structural integrity even after carbonization. Interestingly, anion selection not only influences the cross‐linking and carbonization processes but also significantly modulates the electrochemical performance of the resulting CAs. This is found to be vital in optimizing the overall supercapacitor performance. Electro‐assisted (EA) wetting of the electrodes procures an adaptive and progressive performance enhancement, heralding the advent of sustainable supercapacitors crafted from earth‐abundant materials.
Progress on the Design of Electrocatalysts for Large‐Current Hydrogen Production by Tuning Thermodynamic and Kinetic Factors
Authors: Li Ye , Feng Ao , Dai Linxiu , Xi Baojuan , An Xuguang , Xiong Shenglin , An Changhua
Published: March 2024

Electrochemical water splitting to produce green hydrogen offers a promising technology for renewable energy conversion and storage, as well as realizing carbon neutrality. The efficiency, stability, and cost of electrocatalysts toward hydrogen evolution reaction (HER) and electrocatalytic overall water splitting (EOWS) at large current densities are essential for practical application. In this review, the key factors that determine the catalytic performance of electrocatalysts at large current densities are summarized from the angel of thermodynamic and kinetic correlation. The corresponding design strategies are presented. The electronic structure and density of active sites that affect the adsorption/desorption of intermediates are considered as the thermodynamic aspects, while charge transfer and mass transport capabilities closely associated with electrode resistance and intermediate diffusion are assigned as kinetic effects. Recent development of bifunctional and integrated electrocatalysts toward EOWS is also discussed in detail. Finally, the perspective and direction on the electrocatalytic water splitting under large current density are proposed. This comprehensive overview will offer profound insights and guidance for the continued advancement of this field.
Challenges and Strategies for Endothelializing Decellularized Small‐Diameter Tissue‐Engineered Vessel Grafts
Authors: Ding Heng , Hou Xiaojie , Gao Zhen , Guo Yingqiang , Liao Bin , Wan Juyi
Published: March 2024

Vascular diseases are the leading cause of ischemic necrosis in tissues and organs, necessitating using vascular grafts to restore blood supply. Currently, small vessels for coronary artery bypass grafts are unavailable in clinical settings. Decellularized small‐diameter tissue‐engineered vessel grafts (SD‐TEVGs) hold significant potential. However, they face challenges, as simple implantation of decellularized SD‐TEVGs in animals leads to thrombosis and calcification due to incomplete endothelialization. Consequently, research and development focus has shifted toward enhancing the endothelialization process of decellularized SD‐TEVGs. This paper reviews preclinical studies involving decellularized SD‐TEVGs, highlighting different strategies and their advantages and disadvantages for achieving rapid endothelialization of these vascular grafts. Methods are analyzed to improve the process while addressing potential shortcomings. This paper aims to contribute to the future commercial viability of decellularized SD‐TEVGs.
Label‐Free Single Microparticles and Cell Aggregates Sorting in Continuous Cell‐Based Manufacturing
Authors: Gong Lingyan , He Linwei , Lu Nan , Petchakup Chayakorn , Li King Ho Holden , Tay Chor Yong , Hou Han Wei
Published: March 2024

There is a paradigm shift in biomanufacturing toward continuous bioprocessing but cell‐based manufacturing using adherent and suspension cultures, including microcarriers, hydrogel microparticles, and 3D cell aggregates, remains challenging due to the lack of efficient in‐line bioprocess monitoring and cell harvesting tools. Herein, a novel label‐free microfluidic platform for high throughput (≈50 particles/sec) impedance bioanalysis of biomass, cell viability, and stem cell differentiation at single particle resolution is reported. The device is integrated with a real‐time piezo‐actuated particle sorter based on user‐defined multi‐frequency impedance signatures. Biomass profiling of Cytodex‐3 microcarriers seeded with adipose‐derived mesenchymal stem cells (ADSCs) is first performed to sort well‐seeded or confluent microcarriers for downstream culture or harvesting, respectively. Next, impedance‐based isolation of microcarriers with osteogenic differentiated ADSCs is demonstrated, which is validated with a twofold increase of calcium content in sorted ADSCs. Impedance profiling of heterogenous ADSCs‐encapsulated hydrogel (alginate) microparticles and 3D ADSC aggregate mixtures is also performed to sort particles with high biomass and cell viability to improve cell quality. Overall, the scalable microfluidic platform technology enables in‐line sample processing from bioreactors directly and automated analysis of cell quality attributes to maximize cell yield and improve the control of cell quality in continuous cell‐based manufacturing.
Mixed‐Dimensional Membranes with Double 0D@2D Structures Enable Efficient and Sustainable Water Treatment
Authors: Zhang Zixin , Fu Huaqiang , Wang Zhe , Qian Wei , Zhao Xin , Si Yunfa , Guo Jiannan , Cao Shaowen , He Daping
Published: March 2024

High‐efficiency and sustainable membrane purification technology is highly desirable but unattainable in the field of water treatment. 2D materials are emerging as very promising candidates for water treatment applications. However, membranes assembled by pure 2D materials lack reasonable structural and functional design, usually exhibiting relatively low water permeance, purification performance, and fouling resistance. Here, a mixed‐dimensional membrane is designed to solve the above‐mentioned problems by assembling two kinds of in situ grown 0D@2D functional building blocks of SiO2@GO and TiO2@MXene. Specifically, the obtained membrane exhibits high and maintainable water permeance of 2114 L m−2 h−1 bar−1 as well as high rejection rates toward organic dyes thanks to the plentiful firm water channels constructed by 0D@2D structures and the negative charges on both SiO2@GO and TiO2@MXene, respectively. Moreover, the 0D@2D TiO2@MXene serves as photocatalyst, rendering the composite membrane intriguing self‐cleaning function under UV irradiation, which is verified by the high recovery ratios of water permeance (97.5%) and dye interception rate (98.7%). Thus, this work offers a promising approach for the design of highly efficient and sustainable membrane for separation and purification purposes.