The reduction behavior of sulfurized polyacrylonitrile (SPAN) in lithium-sulfur batteries using a carbonate electrolyte: a computational study.

Lithium-sulfur batteries (LSBs) have attracted attention due to their high theoretical energy density. This and various other advantages, such as the availability and non-toxicity of sulfur, raise interest in LSBs against the background of the energy revolution. However, a polysulfide shuttle mechanism can adversely affect the electrochemical performance of the cell. The sulfur redox properties are influenced, for example, by the electrolyte and the cathode material. Here, a computational study of the discharge process of an LSB with sulfurized poly(acrylonitrile) (SPAN) as the cathode material in combination with a carbonate electrolyte is presented. The nucleation of produced solid Li2S is compared to soluble Li2S. Dominating species are determined by comparing the Gibbs free energy of several species. We found that multiple lithiation steps occur before each Li2S detachment, preventing longer-chain polysulfide cleavage and a polysulfide shuttle. Through nucleating on the nitrogen-rich backbone of SPAN, Li2S units are stabilized by interactions with each other and with the nitrogen atoms. Experimental data show a potential drop and plateau during discharge, which is consistent with the calculated discharge profiles of SPAN with both soluble and nucleated Li2S, and hints at a direct solid-solid transition in the Li-SPAN cell during discharge when using carbonate-based electrolytes.

A generalized hybrid scheme for multireference methods.

A generalization of the hybrid scheme for multireference methods as recently put forward by Saitow and Yanai [J. Chem. Phys. 152, 114 111 (2020)] is presented. The hybrid methods are constructed by defining internal and external excitation spaces and evaluating these two subsets of excitations at different levels of theory. New hybrids that use the mix of internally contracted multireference coupled-cluster, unshifted multireference coupled electron pair, and multireference perturbation methods are derived and benchmarked. A new separation of the excitation space, which combines all singles and doubles excitations to the virtual orbitals into the external space, is also presented and tested. In general, the hybrid methods improve upon their non-hybrid parent method and offer a good compromise between computational complexity and numerical accuracy.

[Newborn Hearing Screening - Results of a Parental Survey in Saxony-Anhalt]. / Neugeborenen-Hörscreening ­ Ergebnisse einer Elternbefragung in Sachsen-Anhalt.

Background: In recent years quality assurance has become an essential part of today's health-care system in the wake of the modern patient-oriented quality management. With the statutory introduction of newborn hearing screening (NHS) in 2009, a quality assurance of these early detection methods has become necessary. The aim of the study was to determine patient satisfaction in relation to the NHS in Saxony-Anhalt. Patients/Methods: During the period from November 2013 to April 2014, 394 parents were retrospectively interviewed about their experiences and expectations in relation to the NHS, using a standardised questionnaire. In total, 21 child care centres and 6 paediatric primary care centres from all over Saxony-Anhalt were involved. Results: It turns out that the majority of parents are satisfied with the NHS and 97.7% are in favour of the offer of an NHS. Of the surveyed parents, 69.3% felt the information as sufficient. However, only 66.2% of parents took a closer look at the leaflet issued by the G-BA. In addition, 17.7% of respondents are dissatisfied with the professional competence of the examining staff. Conclusion: The study shows that the general attitude among parents towards newborn hearing screening was very positive. They felt reassured by it although there are some aspects still open to criticism.

[Prevalence, Risk Factors and Diagnostics of Hearing Impairment in Preterm Infants]. / Prävalenz, Risikofaktoren und Diagnostik von Hörstörungen bei Frühgeborenen.

Introduction: The preterm birth is clearly associated with increased risk of developing congenital hearing impairment. Therefore, special attention must be paid to the postnatal control of auditory function in all preterm infants. The present work investigates if the latest scientific findings regarding prevalence, clinical diagnostics, therapy and risk factors of hearing impairment in premature infants are regularly implemented in daily practice. Methods: At the department of phoniatrics and pediatric audiology of the University Hospital of Magdeburg, the treatment data of 126 preterm children born between 2006 and 2011 were evaluated retrospectively. The additional analysis of all records available at the screening center (n=67 640) covering this period enables drawing conclusions on the total number and prevalence of hearing impairment in preterm infants in Saxony-Anhalt. Results: Almost all premature babies, like mature newborns, underwent postnatal hearing screening of both ears. The data analysis shows that the practical implementation often does not comply with the guideline of the G-BA (Gemeinsamer Bundesausschuss) in all details. For example, the recommended screening method for preterm infants (AABR) or the screening and treatment timing are not always applied in accordance with the guidelines of the G-BA. Discussion: Assessment of the practical implementation of universal newborn hearing screening was planned at the time of the introduction of the hearing screening program by the G-BA. As a part of this investigation, the practical care of vulnerable groups such as preterm infants must be given special attention. Based on the collected data, the diagnostics and therapy should be unified. Regardless of the maternity clinic where the infants were born, there should be the same opportunity for early diagnosis and thus for prognostically better treatment of congenital hearing impairment. Rapid postnatal fitting with hearing aid can stimulate the maturation of the central auditory system and potentially help to avoid problems of hearing and speech development.

Molecular phylogeny and evolution of the cone snails (Gastropoda, Conoidea).

We present a large-scale molecular phylogeny that includes 320 of the 761 recognized valid species of the cone snails (Conus), one of the most diverse groups of marine molluscs, based on three mitochondrial genes (COI, 16S rDNA and 12S rDNA). This is the first phylogeny of the taxon to employ concatenated sequences of several genes, and it includes more than twice as many species as the last published molecular phylogeny of the entire group nearly a decade ago. Most of the numerous molecular phylogenies published during the last 15years are limited to rather small fractions of its species diversity. Bayesian and maximum likelihood analyses are mostly congruent and confirm the presence of three previously reported highly divergent lineages among cone snails, and one identified here using molecular data. About 85% of the species cluster in the single Large Major Clade; the others are divided between the Small Major Clade (∼12%), the Conus californicus lineage (one species), and a newly defined clade (∼3%). We also define several subclades within the Large and Small major clades, but most of their relationships remain poorly supported. To illustrate the usefulness of molecular phylogenies in addressing specific evolutionary questions, we analyse the evolution of the diet, the biogeography and the toxins of cone snails. All cone snails whose feeding biology is known inject venom into large prey animals and swallow them whole. Predation on polychaete worms is inferred as the ancestral state, and diet shifts to molluscs and fishes occurred rarely. The ancestor of cone snails probably originated from the Indo-Pacific; rather few colonisations of other biogeographic provinces have probably occurred. A new classification of the Conidae, based on the molecular phylogeny, is published in an accompanying paper.

[Transparency of the newborn hearing screening system in Germany]. / Transparenz der Umsetzung des Universellen Neugeborenen-Hörscreenings in Deutschland.

AIM: The transparency of implementation of the newborn hearing screening system in Germany is analysed. For this purpose it has been tested whether the current state can be retained and evaluated by using public accessible information channels. METHODS: A selective document analysis with subsequent assessment of the federal states was performed. In the form of a scoring system an assessment approach has been developed based on defined comparison criteria. The selective document analysis was characterised by including only documents which were detected through the internet and medical databases by using defined search terms. RESULTS: A complete survey of the current state of guideline implementation is not available by using public accessible information. The assessment of the federal states reveals an extremely heterogeneous situation with regard to the transparency of the implementation process in Germany. Bavaria has the highest score with 37 points, while Bremen has the lowest score with 3 points. Overall, the supply of information to experts is better constituted compared to that to the population, and respectively, the newborn's parents. CONCLUSION: A meaningful evaluation of the implementation processes in the federal states up to now is urgently required. This is necessary both to optimise the process and to achieve the highest possible quality among patient-centred care structures nationwide.

[Quality of universal newborn hearing screening results : Multicenter analysis of data recorded between 2009 and 2012 in four German states]. / Ergebnisqualität im universellen Neugeborenen-Hörscreening : Multizentrische Analyse von Daten der Jahre 2009 bis 2012 aus 4 Bundesländern.

BACKGROUND: Bearing in mind the impending evaluation of newborn hearing screening in Germany, this study investigated whether multicenter analysis of the screening results from four German states is possible and to what extent the results meet national quality and outcome criteria. MATERIALS AND METHODS: The screening data from 170 hospitals and a total of 533,150 newborns (21 % of all German newborns) from 2009 to 2012 were evaluated according to definite rules and analyzed in terms of averages, as well as over time. RESULTS: During the investigated period and averaged over the hospitals, the quality criteria "percentage of screened newborns" (91.4 %) and "percentage requiring further follow-up" (5.0 %), the "day of screening" (day 4), as well as the target parameter "age at diagnosis" (4.8 months) were not met. Steady improvements were observed over time: in the last year of the evaluation, 95.3 % of children were examined; only 4.8 % required follow-up and the age at diagnosis decreased to 4.2 months. On average, 83 % of the babies were screened before day 4. The steady reduction in variance of most of the variables from the participating hospitals indicates continual improvement. CONCLUSION: A multicenter analysis of screening data is possible and valid in the case of good quality data.

[Otitis media with effusion : frequency, diagnosis, and therapy in early childhood]. / Seromukotympanon : Häufigkeit, Diagnose und Therapie im frühen Kindesalter.

BACKGROUND: Otitis media with effusion (OME) as the most common cause of hearing loss in childhood plays an important role in the follow-up after failed newborn hearing screening (NHS). The introduction of the NHS allows OME to be diagnosed and treated in the first months of life. MATERIAL AND METHODS: In 715 children referred to the Department of Phoniatrics and Pedaudiology of the Ear, Nose, Throat University Hospital of Magdeburg during the period 2006-2010, the prevalence and therapy process of OME during follow-up could be determined. RESULTS: OME was diagnosed in 16 % of the patients. Spontaneous resolution was observed in 37 % of the cases, while 46 % of the children were treated surgically. A substantially increased risk for persistent OME was observed in children with craniofacial dysmorphia or cleft palate. CONCLUSION: Using NHS, OME can be diagnosed and treated early, thus, preventing potential problems in the linguistic, social and intellectual development of children.

Quantum chemical parametrization and spectroscopic characterization of the Frenkel exciton Hamiltonian for a J-aggregate forming perylene bisimide dye.

Quantum chemical and quantum dynamical calculations are performed for a bay-substituted perylene bisimide dye up to its hexameric aggregate. The aggregate structure is determined by employing the self-consistent charge density functional tight-binding (SCC-DFTB) approach including dispersion corrections. It is characterized by a stabilization via two chains of hydrogen bonds facilitated by amide functionalities. Focusing on the central embedded dimer, the Coulomb coupling for this J-aggregate is determined by means of the time-dependent density functional theory (TDDFT) to be -514 cm(-1). Exciton vibrational coupling is treated within the shifted oscillator model from which five strongly coupled modes per monomer are selected for inclusion into a minimal dynamic model. Performing wave packet propagations for a model employing up to 7 electronic states and 30 vibrational modes using the multiconfiguration time-dependent Hartree method, aggregate absorption spectra are obtained and compared to experiment.

Interface characterization of epitaxial Fe/MgO/Fe magnetic tunnel junctions.

Following predictions by first-principles theory of a huge tunnel magnetoresistance (TMR) effect in epitaxial Fe/MgO/Fe magnetic tunnel junctions (MTJs), measured magnetoresistance (MR) ratios of about 200% at room temperature (RT) have been reported in MgO-based epitaxial MTJs. Recently, a MR ratio of about 600% has been reported at RT in MgO-based MTJs prepared by magnetron sputtering, using amorphous CoFeB as the ferromagnetic electrode. These MTJs show great potential for application in spintronic devices. Fully epitaxial MTJs are excellent model systems that enhance our understanding of the spin-dependent tunneling process as the interface is well defined and can be fully characterized. Both theoretical calculations and experimental results clearly indicate that the interfacial structure plays a crucial role in the coherent tunneling across a single crystal MgO barrier, especially in epitaxial MgO-based MTJs grown by molecular beam epitaxy (MBE). Surface X-ray diffraction, Auger electron spectroscopy, X-ray absorption spectra, and X-ray magnetic circular dichroism techniques have been reported previously for interface characterization. However, no consistent viewpoint has been reached on the interfacial structures (such as FeO layer formation at the bottom Fe/MgO interface), and it is still an open issue. In this article, our recent studies on the interface characterization of MgO-based epitaxial MTJs by X-ray photoelectron spectroscopy, high resolution transmission electron microscopy, and spin-dependent tunneling spectroscopy, will be presented.

Local injection of infliximab in severe fistulating perianal Crohn's disease: an open uncontrolled study.

BACKGROUND: Perianal fistulas are frequent complications of Crohn's disease. Intravenous infliximab can control perianal disease and promote perianal fistula closure. Perifistular infliximab injections have been proposed for patients who are intolerant or unresponsive to intravenous therapy. The aim of this study was to assess the long-term efficacy of surgical treatment combined with local infliximab therapy. METHODS: A prospective cohort study was designed. Twelve patients with Crohn's disease and high/complex transphincteric and intrasphincteric perianal fistulas refractory to other treatment were submitted to core-out fistulectomies, plus perifistular injections of infliximab (20-25 mg in 15-20 ml of 5% glucose) every 4-6 weeks. The main outcome measure was the clinical closure of all perianal fistulas. A 95% confidence interval was calculated for short- and long-term fistula closure rates. RESULTS: None of the procedures were associated with local or systemic adverse effects. Four patients did not complete treatment, two because of relapse of intestinal symptoms, which required intravenous infliximab. In one case, treatment with intravenous infliximab was complicated by a hypersensitivity reaction. Eight patients continued treatment until all perianal fistulas were closed and setons were removed (median: 5 sessions). Persistent closure was observed in seven (87.5%, 95% CI: 47.4-99.6) of the eight patients 12 months after completion of treatment and in five (62.5%; 95% CI: 24.5-91.5) of eight at the end of follow-up (range: 19-43 months, median: 35 months). CONCLUSIONS: The cohort we examined is small, but fistulectomy combined with repeated perifistular injections of infliximab appears to be safe and may help in fistula healing. However, in most patients, permanent closure of all fistulas is not achieved.

Azathioprine for prevention of clinical recurrence in Crohn's disease patients with severe endoscopic recurrence: an IG-IBD randomized double-blind trial.

OBJECTIVE: The recurrence of Crohn's Disease after ileo-colonic resection is a crucial issue. Severe endoscopic lesions increase the risk of developing early symptoms. Prevention and treatment of post-operative Endoscopic Recurrence (ER) have been studied with conflicting results. We compare effi cacy of azathioprine (AZA) vs. high-dose 5-aminosalicylic acid (5-ASA) in preventing clinical recurrence and treating severe post-operative ER. PATIENTS AND METHODS: We performed a 1-year multicenter randomized double-blind double-dummy trial. Primary end-points were endoscopic improvement and therapeutic failure (clinical recurrence or drug discontinuation due to lack of efficacy or adverse events) 12 months after randomization. We also performed a post-trial analysis on symptomatic and endoscopic outcomes 10 years after the beginning of the trial, with a median follow-up of 60 months. RESULTS: Therapeutic failure occurred in 8 patients (17.4%) within 12 months from randomization, with no significant difference between patients treated with 5-ASA (20.8%, 5 patients) and those with AZA (13.6%, 3 patients). Therapeutic failure was due to clinical recurrence in the 5-ASA group and to adverse events in the AZA group. Endoscopic improvement at 12 months was observed in 8 patients, 2 (11.8%) in the 5-ASA group and 6 (30%) in the AZA group. No serious adverse event was recorded. At the post-trial analysis (median follow-up 60 months), 47.8% (22/46) of patients experienced clinical recurrence: 54.2% (13/24) in the 5-ASA group and 40.9% (9/22) in the AZA group, p=0.546. Patients treated with AZA had lower risk of drug escalation. Clinical recurrence was associated with smoking (p=0.031) and previous surgery (p=0.003). CONCLUSIONS: Our trial indicates that there was no difference in terms of treatment failure between 5-ASA and AZA in patients with severe ER. The main limit of AZA is its less favorable safety profile.

Radula Tooth Structure of the Gastropod Conus imperialis Elucidated by Scanning Electron Microscopy.

Scanning electron microscopy of the hollow, harpoon-like radula tooth of the toxoglossan gastropod Conus has elucidated the structure and relationships of its component parts: apex, cutting edge, barbs, serration, adapical and basal openings of the lumen, external and internal folds of the shaft, and base. The functional roles of these components in prey capture are proposed.

Multicentre approach to epidemiological aspects of craniosynostosis in Germany.

We know of no current published data on the prevalence of craniosynostosis in Germany, so our objective in this study was to contribute to the limited knowledge of its epidemiology by assessing time trends, the frequency of prenatal diagnosis, and the timing of diagnosis and treatment. Data were collected in Saxony-Anhalt during the period 2000-17, and we designed a retrospective multicentre cohort study. The prevalence was 4.8 cases of craniosynostosis/10 000 births, and did not increase during that time. We compared the data of 91 patients with those of 273 controls. There were 75 boys and 16 girls (ratio 4.7:1). Fifty-one children had isolated craniosynostosis, consisting of 46 with a single-suture, and five with a multisuture, synostosis. Twenty-nine were associated with other congenital malformations, and 11 were syndromic. Three cases had been diagnosed prenatally, and 34 had skull deformities diagnosed immediately after birth at a mean (SD) age of 3.4 (4.7) months. The mean (SD) age at the time of first admission to hospital in one of the three surgical centres of Saxony-Anhalt was 5.9 (5.5) months, and 65 patients were operated on at a mean age of 9.1 (6.3) months. In contrast to published reports we found a prevalence of 4.8 cases of craniosynostosis/10 000 births that did not increase during the period 2000-16. Although we found a low prenatal detection rate, the diagnosis and treatment in this cohort study seemed timely.

Infliximab in severe ulcerative colitis: short-term results of different infusion regimens and long-term follow-up.

BACKGROUND: Severe ulcerative colitis is a life-threatening disorder, despite i.v. glucocorticoids treatment. Infliximab has been proposed as a safe rescue therapy. AIM: To evaluate short- and long-term effectiveness and safety of infliximab in severe refractory ulcerative colitis. METHODS: Eighty-three patients with severe ulcerative colitis (i.v. glucocorticoids treatment-refractory) were treated with infliximab in 10 Italian Gastroenterology Units. Patients underwent one or more infusions according to the choice of treating physicians. Short-term outcome was colectomy/death 2 months after the first infusion. Long-term outcome was survival free from colectomy. Safety data were recorded. RESULTS: Twelve patients (15%) underwent colectomy within 2 months. One died of Legionella pneumophila infection 12 days after infliximab. Early colectomy rates were higher in patients receiving one infusion (9/26), compared with those receiving two/more infusions (3/57, P = 0.001, OR = 9.53). Seventy patients who survived colectomy and did not experience any fatal complications were followed-up for a median time of 23 months; 58 patients avoided colectomy during the follow-up. Forty-two patients were maintained on immunosuppressive drugs. No clinical features were associated with outcomes. CONCLUSIONS: Infliximab is an effective and relatively safe therapy to avoid colectomy and maintain long-term remission for patients with severe refractory ulcerative colitis. In the short term, two or more infusions seem to be more effective than one single infusion.

Compartmental models of mammalian motoneurons of types S, FR and FF and their computer simulation.

Mathematical models of motoneurons (MNs) of types S, FR and FF were developed based on cat MN data. Each of the three models has an initial segment, a soma and a dendritic tree. The initial segment and the soma include models of several types of ionic currents, including a calcium-dependent slow potassium current. The dendritic tree is modeled as a series association of several electrically passive cylinders. Afterhyperpolarization parameters, current to frequency relation and the responses to input current steps, ramps and sinusoids were used for model validation. The effects of sinusoidally varying synaptic inputs at different levels of the dendritic tree were studied by computer simulation. The corresponding frequency response functions resulted of lowpass type with cutoff frequencies from 10 to 40 Hz, for synapses occurring more distally or more proximally, respectively. The nonlinear effects caused by two sinusoidally varying synaptic conductances (at 7 and 11 Hz), acting at different dendritic segments, were quantified by spectral analysis of the current reaching the soma. The simulations pointed to two main nonlinear effects: (i) harmonics of the two input frequencies (e.g., 14 Hz) and (ii) intermodulation terms (e.g., 4 Hz). When the two synaptic inputs occurred on more distal dendritic compartments the nonlinear effects were more pronounced.

Measurement of turbulent electron temperature fluctuations on the ASDEX Upgrade tokamak using correlated electron cyclotron emission.

Turbulent temperature fluctuations are measured on the ASDEX Upgrade tokamak using pairs of closely spaced, narrow-band heterodyne radiometer channels and a standard correlation technique. The pre-detection spacing and bandwidth of the radiometer channel pairs is chosen such that they are physically separated less than a turbulent correlation length, but do not overlap. The radiometer has 4 fixed filter frequency channels and two tunable filter channels for added flexibility in the measurement position. Relative temperature fluctuation amplitudes are observed in a helium plasma to be δT/T = (0.76 ± 0.02)%, (0.67 ± 0.02)%, and (0.59 ± 0.03)% at normalised toroidal flux radius of ρtor = 0.82, 0.75, and 0.68, respectively.

Infliximab in the treatment of Crohn's disease: predictors of response in an Italian multicentric open study.

BACKGROUND: Almost 20% of patients with active Crohn's disease are refractory to conventional therapy. Infliximab is a treatment of proven efficacy in this group of patients and it is not clear which variables predict a good response. AIMS.: To evaluate the role of infliximab looking at the predictors of response in a large series of patients with Crohn's disease. PATIENTS AND METHODS: Five hundred and seventy-three patients with luminal refractory Crohn's disease (Crohn's Disease Activity Index (CDAI)>220-400) (312 patients) or with fistulising disease (190 patients) or both of them (71 patients) were treated with a dose of 5 mg/kg in 12 Italian referral centres. The primary endpoints of the study were clinical response and clinical remission for luminal refractory and fistulising disease. We evaluated at univariable and multivariable analysis the following variables: number of infusions, sex, age at diagnosis, smoking habit, site of disease, previous surgery, extraintestinal manifestations and concomitant therapies, and type of fistulas. RESULTS: Patients with luminal refractory disease: 322 patients (84.1%) had a clinical response and 228 (59.5%) reached clinical remission. Patients with fistulising disease: 187 patients (72%) had a reduction of 50% of the number of fistulas and in 107 (41%) a total closure of fistulas was observed. For luminal disease, single infusion (OR 0.49, 95% CI 0.28-0.86) and previous surgery (OR 0.53, 95% CI 0.30-0.93) predicted a worse response for fistulising disease. Other fistulas responded worse than perianal fistulas (OR 0.57, 95% CI 0.303-1.097). CONCLUSION: In Crohn's disease infliximab is effective in luminal refractory and in fistulising disease. A single infusion and previous surgery predicted a worse response in luminal disease whereas perianal fistulas predicted a better response than other type of fistulas.

Thyrotropin increases malic enzyme messenger ribonucleic acid levels in rat FRTL-5 thyroid cells.

The addition of TSH to FRTL-5 thyroid cells induces a 7- to 8-fold increase in the steady state level of malic enzyme [L-malate-NADP+ oxidoreductase (decarboxylating); EC 1.1.1.40] mRNA, but does not alter beta-actin mRNA levels. Insulin alone or together with TSH has no effect on malic enzyme mRNA. The effect of TSH is not the result of thyroid hormone formation, since the addition of T3 in the presence or in the absence of TSH and the addition of 5% serum (which includes T3 and T4) have no effect. Forskolin (10(-6) M) reproduces the TSH effect, suggesting that cAMP is involved.

Thyrotropin regulation of malic enzyme in FRTL-5 rat thyroid cells.

TSH-induced increases in malic enzyme mRNA levels in FRTL-5 rat thyroid cells are paralleled by increases in malic enzyme activity and are mimicked by 8-bromo-cAMP. Apparent approximately 4 h after TSH challenge and maximal after 16 h, they decline by 24 h and are at basal levels by 48 h. The increase occurs in the absence of a measurable effect of TSH on DNA synthesis related to cell growth, since [3H] thymidine incorporation into DNA is still at basal levels 24 h after TSH challenge and is maximal only at 48 h. A protein(s) whose formation is inhibited by cycloheximide appears to be critical to the ability of TSH to increase malic enzyme mRNA levels. Thus, cycloheximide given 30 min before TSH prevents the hormone-induced increase in malic enzyme mRNA; also, when given 24 h after TSH, cycloheximide accelerates the loss of the TSH-induced increase in malic enzyme mRNA. In neither case does cycloheximide affect beta-actin mRNA levels. A second factor(s) whose formation is prevented by actinomycin-D appears to be important for the decrease in malic enzyme mRNA levels seen 24 and 48 h after TSH challenge. Thus, in experiments in which it is given 24 h after TSH, actinomycin-D preserves the hormone-induced increase in malic enzyme mRNA levels rather than accelerating the decrease, as does cycloheximide. In the same experiment, beta-actin mRNA levels decrease to less than 10-20% of control values over the same period; this factor also, therefore, appears to exhibit some degree of specificity.(ABSTRACT TRUNCATED AT 250 WORDS)