Central European 2018 hot drought shifts scots pine forest to its tipping point.

The occurrence of hot drought, i.e. low water availability and simultaneous high air temperature, represents a severe threat to ecosystems. Here, we investigated how the 2018 hot drought in Central Europe caused a tipping point in tree and ecosystem functioning in a Scots pine (Pinus sylvestris L.) forest in southwest Germany. Measurements of stress indicators, such as needle water potential, carbon assimilation and volatile organic compound (VOC) emissions, of dominant P. sylvestris trees were deployed to evaluate tree functioning during hot drought. Ecosystem impact and recovery were assessed as ecosystem carbon exchange, normalized difference vegetation index (NDVI) from satellite data and tree mortality data. During summer 2018, needle water potentials of trees dropped to minimum values of -7.5 ± 0.2 MPa, which implied severe hydraulic impairment of P. sylvestris. Likewise, carbon assimilation and VOC emissions strongly declined after mid-July. Decreasing NDVI values from August 2018 onwards were detected, along with severe defoliation in P. sylvestris, impairing ecosystem carbon flux recovery in 2019, shifting the forest into a year-round carbon source. A total of 47% of all monitored trees (n = 368) died by September 2020. NDVI recovered to pre-2018 levels in 2019, likely caused by emerging broadleaved understorey species. The 2018 hot drought had severe negative impacts on P. sylvestris. The co-occurrence of unfavourable site-specific conditions with recurrent severe droughts resulted in accelerated mortality. Thus, the 2018 hot drought pushed the P. sylvestris stand towards its tipping point, with a subsequent vegetation shift to a broadleaf-dominated forest.

[Chronic thromboembolic pulmonary hypertension: Time delay from onset of symtoms to diagnosis and clinical condition at diagnosis]. / Chronisch thromboembolische pulmonale Hypertonie: Latenz bis zur Diagnosesicherung und klinischer Zustand bei Diagnosestellung.

BACKGROUND AND AIM: Chronic-thromboembolic pulmonary hypertension (CTEPH) is a serious complication of acute pulmonary embolism (PE). In untreated patients prognosis is poor. It depends on WHO-functional class. A delay from onset of symptoms and diagnosis can lead to a further worsening of prognosis. A pulmonary endarterectomy is the treatment of choice. We aimed to evaluate the time delay from onset of symptoms to diagnosis and the WHO-functional class at primary diagnosis in patients with CTEPH. PATIENTS AND METHODS: Retrospective analysis of data from 70 monocentrically registered patients (48 women, 22 men, mean age 66,2 years  ± â€Š13,8 years) with confirmed CTEPH from the pulmonary hypertension expert center Missionsärztliche Klinik. Diagnostic work-up was performed according to the current guidelines. RESULTS: Mean delay from onset of symptoms to diagnosis of CTEPH was 18 ±â€Š26 months. Time delay was only slightly shorter in patients with a history of PE (n = 56; 81 %) than in patients without a history of PE (n = 13; 19 %): 16,9  ± â€Š23,8 vs. 23,5 â€Š± â€Š36,9 months. Time delay was higher in patients who received vasoactive medication before the first contact with a PH expert center and in patients who were classified as technically not suitable for a thrombendarterectomy. 38 patients with a history of acute PE did not have a period without symptoms. In 18 patients symptoms had transiently gone after PE. More than 70 % presented in WHO functional class III or IV. CONCLUSION: Time delay between onset of symptoms and diagnosis of CTEPH and referral to a PH expert center is long and the majority of patients presented in WHO-functional class III or IV. Prognosis is poor in untreated patients and getting worse with a higher WHO-functional class. For this reason, and because CTEPH can be cured by a pulmonary endarterectomy, each patient with suspected PH should be referred to a PH expert center to exclude CTEPH.

Modulation of mu opioid receptor desensitization in peripheral sensory neurons by phosphoinositide 3-kinase gamma.

G protein-coupled opioid receptors undergo desensitization after prolonged agonist exposure. Recent in vitro studies of mu-opioid receptor (MOR) signaling revealed an involvement of phosphoinositide 3-kinases (PI3K) in agonist-induced MOR desensitization. Here we document a specific role of the G protein-coupled class IB isoform PI3Kgamma in MOR desensitization in mice and isolated sensory neurons. The tail-withdrawal nociception assay evidenced a compromised morphine-induced tolerance of PI3Kgamma-deficient mice compared to wild-type animals. Consistent with a role of PI3Kgamma in MOR signaling, PI3Kgamma was expressed in a subgroup of small-diameter dorsal root ganglia (DRG) along with MOR and the transient receptor potential vanilloid type 1 (TRPV1) receptor. In isolated DRG acute stimulation of MOR blocked voltage-gated calcium currents (VGCC) in both wild-type and PI3Kgamma-deficient DRG neurons. By contrast, following long-term opioid administration the attenuating effect of MOR was strongly compromised in wild-type DRG but not in PI3Kgamma-deficient DRG. Our results uncover PI3Kgamma as an essential modulator of long-term MOR desensitization and tolerance development induced by chronic opioid treatment in sensory neurons.

Synthesis of spherical porous silicas in the micron and submicron size range: challenges and opportunities for miniaturized high-resolution chromatographic and electrokinetic separations.

Classical silica technology has reached its limit with respect to an ultimate minimum particle size of about 2 microm in diameter. Here, a novel process is presented which allows one to synthesize porous silica beads and control their particle diameter in situ, within the range of 0.2-2.0 microm. As a result, no sizing is required and losses of silica are avoided. Furthermore, the process enables one to control in situ the pore structural parameters and the surface chemistry of the silica beads. Even though surface funtionalized silicas made according to this process can principally be applied in fast HPLC the column pressure drop will be high even for short columns. In addition, the column efficiency, expressed in terms of the theoretical plate height is about H-2d(p) in the best case and limited by the A and C term of the Van Deemter equation. In other words the gain in total plate number when using 1-2 microm silica beads in short columns is minimal as compared to longer columns packed with 5 microm particles. Capillary electrochromatography (CEC) as a hybrid method enables the application of micron size as well as submicron size particles. This consequently enhances column efficiency by a factor of 5-10 when compared to HPLC. The use of short CEC columns packed with submicron size silicas provides the basis for fast and efficient miniaturized systems. The most significant feature of CEC as compared to HPLC is that the former allows one to resolve polar and ionic analytes in a single run. An alternative method for miniaturization is capillary electrophoresis (CE) which generates extremely high efficiencies combined with fast analysis. Its application, however, is limited to ionic substances.

High-intensity pulse propagation in semiconductors: on-resonant self-induced transmission and effects in the continuum.

We perform high-intensity pulse propagation experiments in semiconductors. On a free exciton resonance, we demonstrate coherent Self-Induced Transmission. Tuning the laser towards higher energy, thus exciting continuum states, the degree of transmission is reduced. The pulse breakup vanishes. Increasing the pulse intensity by several orders of magnitude, pulse breakup can be observed again.

Pore Size Analysis of MCM-41 Type Adsorbents by Means of Nitrogen and Argon Adsorption.

Methods of nonlocal density functional theory (NLDFT), proposed recently for predictions of adsorption equilibrium and calculations of pore size distributions in micro- and mesoporous materials, were tested on reference MCM-41 materials. Five newly synthesized MCM-41 adsorbents with presumably uniform pore channels varying from 32 to 45 Å were characterized by X-ray diffraction (XRD), nitrogen adsorption at 77 K, and argon adsorption at 77 and 87 K. New sets of intermolecular interaction parameters of the NLDFT model for N2 and Ar adsorption on MCM-41 were determined. The parameters were specified to reproduce the bulk liquid-gas equilibrium densities and pressures, liquid-gas interfacial tensions, and standard adsorption isotherms on nonporous surfaces in the multilayer adsorption region. The pore size distributions calculated from the desorption branches of the experimental isotherms measured at three different temperatures were consistent with each other. Comparison of the NLDFT-calculated pore sizes with XRD data showed that the thickness of pore walls in the MCM-41 samples under consideration varied from ca. 6 to 12 Å. We found no correlation between the pore size and the pore wall thickness. The results obtained support the NLDFT model as a suitable tool for characterizing nanoporous materials and predicting adsorption equilibrium. The MCM-41 samples studied can be used as references for adsorption measurements. Copyright 1998 Academic Press.

[Sirenomelia--prenatal diagnosis and clinical consequences of a rare abnormality]. / Sirenomelie--pränatale Diagnose und klinische Konsequenz einer seltenen Fehlbildung.

Sirenomelia or the mermaid syndrome is a rare birth defect, often combined with severe malformations of the urogenital system and the lower gastrointestinal tract. The incidence is about one case in 60,000. Ultrasound can be very important in early detection of this deformity. Because of the high incidence of oligohydramnios amnioninfusion could be helpful. Also a magnetic resonance radiographia in the prenatal period could be performed. We report three cases of sirenomelia and in addition the literature is reviewed and discussed.

Precipitation of overt encephalopathy in the portacaval shunted rat: towards the development of an adequate model of chronic portal systemic encephalopathy.

OBJECTIVE: To assess the feasibility of developing a model of overt portal-systemic encephalopathy (PSE) in rats with a surgically constructed portacaval anastomosis (PCA). DESIGN: The ability of increasing the load of nitrogenous substances in the gastrointestinal tract and/or further decreasing hepatocellular function to induce overt encephalopathy in rats with a PCA was determined. METHODS: The load of nitrogenous substances in the gastrointestinal tract was increased by feeding a pure horse-meat diet or by gavaging with blood. Partial hepatectomy and the induction of cirrhosis were used to decrease hepatocellular function further. The severity of encephalopathy was assessed using a neurobehavioural scale. RESULTS: Overt encephalopathy was not induced in rats by a PCA alone, by a PCA plus a horse-meat diet, by a PCA plus induction of cirrhosis, or by a PCA plus a 50% hepatectomy. Predominantly mild, but overt, encephalopathy was induced in rats with a PCA alone by gavaging with blood and a higher incidence of more severe overt encephalopathy was induced in rats with a PCA combined with either cirrhosis or partial hepatectomy by gavaging with blood. Although these models of PSE were associated in some instances with plasma ammonia concentrations about 25 times higher than normal, no seizures were observed. CONCLUSION: A syndrome that resembles overt PSE in humans can be induced in the rat with a PCA by further reducing hepatocellular function and also gavaging with blood. Although the rat with a PCA has been. extensively used as a model in studies relating to the pathogenesis of PSE, a syndrome resembling overt PSE in humans cannot readily be induced in rats with a PCA.

Influence of type of diet and incubation time on in sacco release of Cu, Fe, Mn and Zn from Italian ryegrass, untreated and ammonia treated wheat straw.

Artificially dried ryegrass, untreated and ammonia-treated wheat straw were ground and incubated in nylon bags in the rumen of three sheep each fed with diets based on roughage or concentrate. Dry matter degradability, the concentration and the release of the trace elements Cu, Fe, Mn and Zn from the incubated feeds were measured after 0 (washing loss), 6, 12, 24, 48 and 72 h rumen incubation time. Dry matter degradability, trace element concentration and their release were significantly influenced by the kind of incubated feeds, incubation time and feeding of sheep. Cu- (1.8-6.9 mg kg-1 DM) and Zn concentrations (36-103 mg kg-1 DM) of straw residues in the bags were much higher than those of original straw (1.2-1.6 and 8.1-9.9 mg kg-1 DM resp.). The inflow of Cu and Zn in the bags containing straw residues was higher than their release. The Cu-, Fe- and Mn-release from ryegrass was similar to the dry matter degradability, but the Zn-release was much lower.

Risk of endocarditis in transesophageal echocardiography.

The risk of endocarditis associated with transesophageal echocardiography was studied in 101 patients. To evaluate possible bacteremia, blood cultures were performed on samples from consecutive patients who did not have clinical or laboratory evidence of infection. The broth blood culture Signal system was used in all patients, and additionally, the lysis-centrifugation technique was performed in a subgroup of 40 patients to further ameliorate recovery of rapidly phagocytosed germs. Comprehensive criteria for differentiation between true bacteremia and possible contamination were provided by means of simultaneous blood sampling from two separate venipuncture sites and skin specimens from the venipuncture area. Oropharyngeal specimens were cultured for evaluation of possible association of oropharyngeal flora with positive blood culture findings. They revealed facultative pathogenic isolates, as well as physiologic residental flora, in 15 patients. All blood isolates that were recovered simultaneously 6 minutes after the procedure were found to be sterile. Correspondingly, clinical follow-up for 2 weeks was uneventful with regard to episodes of infection. These results indicate that the risk of bacteremia associated with transesophageal echocardiography is extremely low. Thus endocarditis prophylaxis is not required for this procedure.

Nicotianamine and the distribution of iron into the apoplasm and symplasm of tomato (Lycopersicon esculentum Mill.) : I. Determination of the apoplasmic and symplasmic iron pools in roots and leaves of the cultivar Bonner Beste and its nicotianamine-less mutant chloronerva.

The apoplasmic and symplasmic iron pools were determined in roots and leaves of Lycopersicon esculentum Mill. cv. Bonner Beste and its mutant chloronerva. The mutant is auxotrophic for the ubiquitous plant constituent nicotianamine (NA) and exhibits an impaired iron metabolism. Formation of apoplasmic iron pools in roots was dependent on the iron source in the nutrient solution. With Fe-ethylenediaminedi-(2-hydroxyphenylacetate) (FeEDDHA) only a very small apoplasmic iron pool was formed in the roots of both genotypes. Plants grown with FeEDTA increased their apoplasmic iron pool with increasing exogenous iron concentrations in the nutrient solution. The size of the apoplasmic pools in roots did not differ between the wild-type and the mutant (about 85 µmol Fe · g(-1) DW). By contrast, the symplasmic iron concentrations in roots and leaves of the mutant were significantly higher when compared to the wild-type. An exogenous NA supply to the leaves of the mutant reduced the high symplasmic iron concentrations to the level of the wild-type. Mutant leaves exhibited a gradient of symplasmic iron concentrations depending on the developmental age of the leaves. The oldest leaves contained considerably more symplasmic iron than the youngest. The results demonstrate that the apparent iron deficiency of the mutant is not the consequence of an impaired iron transport from the apoplasm to the symplasm. Therefore, it is concluded that NA is not required for the transport of Fe(II) through the plasmalemma into the cell.

Portacaval shunt as an experimental model of impaired hepatic release of vitamin A in liver disease.

Vitamin A concentrations in serum and liver were studied in rats with a portacaval shunt for 48 days after shunt surgery. In addition, serum and tissue concentrations of zinc were analyzed. Following portacaval shunting serum vitamin A concentration decreased to 25% of the level in sham-operated controls, whereas serum zinc concentration decreased to 80%. The mean urinary excretion rate of zinc increased in shunted rats [18.7 +/- 2.1 micrograms/day (0.28 +/- 0.03 mumol/day)] compared with controls [13.8 +/- 1.7 micrograms/day (0.21 +/- 0.03 mumol/day)] (P less than 0.01). The concentration of retinol and total retinoids in liver tissue increased 2-3-fold in rats with a portacaval shunt, and the ratio of retinol to retinoids was slightly increased. The differences were reduced when the total organ content was calculated, because of the reduced liver weight in the shunted rats. The concentration of zinc in liver tissue decreased in rats with portacaval shunts [30.8 +/- 4.9 micrograms/g wet wt (0.47 +/- 0.07 mumol/g) vs. 35.6 +/- 3.7 micrograms/g wet wt (0.54 +/- 0.06 mumol/g) in controls; P less than 0.01]. The concentration of zinc was inversely correlated with retinol (r = -0.52, P less than 0.05) and total retinoid levels (r = -0.70, P less than 0.05) in rats with portacaval shunts but not in controls. The data are consistent with the hypothesis of an impaired release of vitamin A from the liver in rats with portacaval shunts, an impairment that could be due to liver zinc deficiency.

[Autoradiography determination of the GABA(A) receptor density in the brain of rats with portacaval shunt]. / Autoradiographische Bestimmung der GABA(A)-Rezeptorendichte im Gehirn von Ratten mit portokavalem Shunt.

Quantitative autoradiography was used to assess the densities of gamma-aminobutyric acid (GABAA) receptors in the brains of rats with a portacaval end-to-side shunt (PCA). The shunt alone induced only mild encephalopathy with ataxia and decreased locomotion. Aggravation of the encephalopathy was achieved by gavage feeding of packed erythrocytes or by induction of severe hyperammonemia by intraperitoneal injection of urease. Gavage feeding of erythrocytes led to severe encephalopathy in about 50% of the animals with PCA. The combination of PCA and urease treatment caused severe encephalopathy in every animal. The serum ammonia concentration increased 5 times normal by PCA alone, 20 times normal by gavage feeding of erythrocytes and more than 30 times normal by urease-treatment of the PCA-animals. For autoradiography, coronal slices were cut at the level of the hippocampal formation and through the cerebellum. Radioligand binding was measured using as a ligand 3H-muscimol, a specific GABAA receptor agonist. The specific binding of 3H-muscimol was assessed densitometrically in several microregions of cerebral cortex, hippocampus and cerebellar cortex. No significant differences were observed between the magnitude of ligand binding to specific microregions of brains from normal animals, animals with PCA without overt encephalopathy and animals with severe encephalopathy induced by a combination of PCA and gavage feeding of erythrocytes or urease treatment.

Increased bioavailability of enzymes of eicosanoid synthesis in hepatic and extrahepatic tissues after portacaval shunting.

Metabolites of arachidonic acid have been attributed to severe circulatory, metabolic and hormonal alterations in patients with chronic liver disease. In order to study changes of the tissue-specific availability of enzymes of eicosanoid synthesis, we used portacaval-shunted rats, as this model exhibits many clinical and biochemical similarities to patients suffering from cirrhosis of the liver. Microsomal mass and maximal velocity of prostaglandin H synthase, the initial enzyme of prostaglandin synthesis, were markedly and permanently increased after shunting in both hepatic and extrahepatic tissues as compared to those of sham-operated rats. Maximal velocity of thromboxane synthase and prostacyclin synthase, two more peripheral enzymes of the arachidonic acid cascade, were tissue-specifically enhanced, whereas the apparent affinities (Km) remained unchanged. Determination of 5-lipoxygenase activity in tissue preparations disclosed a preferential increase in the liver, lung and renal cortex after portacaval shunting. Furthermore, exposure to endotoxin closely mimicked the shunting-induced changes. These results suggest that after portacaval shunting and possibly in patients with advanced liver disease, profound abnormalities at the level of local enzyme expression might play a pathophysiologically important role in the control of eicosanoid synthesis.

The lead status of horses from central Europe depending on breed, sex, age and living area.

The breed of horses took a significant effect on the Pb content of animals with a normal Pb supply. Warm-blooded horses stored more Pb in skeleton, kidneys, liver and cerebrum than heavy horses. The sex only had the trend of influencing the Pb status. Mares with a normal Pb supply incorporated more Pb than geldings. Age only took a slight effect on the skeleton. Older horses stored more Pb in the metatarsal bone than younger ones. The Pb content of horse meat was not influenced by Pb exposure. Pb was not additionally deposited in the musculature. The Pb offer of the living area took a significant effect on the Pb status of horses. Skeleton, liver and kidneys indicated the site-specific influences significantly.

[Hyperestrogenemia following various shunt operations: on the role of estrogens in the development of focal nodular hyperplasia of the liver]. / Hyperöstrogenämie nach verschiedenen Shuntoperationen: Zur Rolle der Ostrogene bei der Entstehung der fokal nodulären Hyperplasie der Leber.

Hormones especially estrogens have been suspected to induce liver cell tumours or hepatic focal nodular hyperplasia (FNH). In rats 6 months after portocaval anastomosis (PCA) the occurrence of FNH has been observed. Modified portocaval anastomosis (mPCA) does not lead to FNH. To test the concept of estrogen induced tumour formation we measured in both groups as well as in a shamoperated control group (SOP) the levels of estradiol (E2), estrone (E1) and of testosterone (T). In a further experiment the hormone levels were measured in rats with portocaval transposition (PCT), an operation which leads to high gonadal hormone production. In groups of 6 male rats each (280-300 g) either SOP, PCA, mPCA or PCT were performed. 30 days later the blood levels of E2, E1, and of T were measured by radioimmunoassay. In PCT-rats hormone levels were measured in the blood synchronously taken from the inferior vena cava (prehepatic) and from the heart (posthepatic), to get an information of the hepatic hormone degradation. After PCA the median level of E2 (77 pg/ml) and E1 (63 pg/ml) are significantly elevated when compared with SOP-rats (41 and 43 pg/ml). Equally after mPCA the E2 and E1 levels are significantly higher (61 and 70 pg/ml) than in controls rats. In contrast the concentrations of T are significantly reduced (PCA 0.03, mPCA 0, 10, SOP 1.0 ng/ml). PCA as well as mPCA result in a hyperestrogenic and hypoandrogenic status. When PCA and mPCA are compared, only the testosterone blood levels are significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

[Ileus symptoms due to 3 distinctively differentiated small intestine carcinomas in nontropical sprue]. / Ileussymptomatik durch drei unterschiedlich differenzierte Dünndarmkarzinome bei einheimischer Sprue.

Recently recurring abdominal pain, bouts of diarrhoea and weight-loss of 15 kg developed in a 50-year-old woman who had for 18 years been treated by diet for nontropical sprue. She was hospitalized for signs of mechanical ileus. Radiological examination revealed three stenosing small intestine tumours, one of them obstructing the lumen. After resection of the affected segments, with end-to-end anastomosis, histological, histological examination of the surgical specimens demonstrated three small intestine carcinomas of different grades of differentiation. The largest tumour had already metastasized to four regional lymph nodes. This case illustrates the potentially precancerous nature of nontropical sprue which has been present for many years and thus requires careful follow-up.

Bladder carcinogenesis in portacaval shunt rats.

The induction of transitional cell bladder tumors following portacaval shunt (PCA) in rats was investigated. Thirty-five (29 males; 6 females) out of 86 animals developed a carcinoma. The highest incidence of tumors (73%) was seen in control animals without a PCA but with implantation of a bladder stone. PCA rats had an induction rate of 34% and a spontaneous bladder tumor was seen in 2/13 sham-operated controls. All rats with a bladder tumor also had urolithiasis; 34 rats had bladder stones in 1 rat had kidney stones. The induction rate in males was 29/52, 55.7% compared to 6/34, 17.6% in females. All tumors were transitional cell carcinomas and were graded G0-GIII [1(G0); 24 (GI); 1 (GI-II); 9 (GII)] accompanied in 20 cases by squamous cell metaplasia. Chronic irritation by stones and infection are the most likely causes of tumor development; however, other mechanisms such as excretion of carcinogens or tumor promoters cannot be completely excluded. The sex difference in stone formation - and tumor induction - are subject to further investigations.