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.

Histiocyte X positivity for nonspecific esterase.

The cell membrane and X bodies of histiocytes X from two cases of eosinophilic granuloma were stained by nonspecific esterase. The results show that histiocytes X possess a cell membrane exoenzyme similar to that of other histiocytes, such as alveolar macrophages, but the role of the X body as related to enzyme activity remains an unknown.

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.

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.

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.

Renal bile acid excretion as a cause of neoplastic lesions in the urinary tract after total portacaval shunt in the normal rat?

Rats with a total portacaval anastomosis (PCA, PC-SS) develop preneoplastic and neoplastic lesions in the urinary tract. In contrast to this, animals with a modified shunt (mPCA) do not develop these lesions. To evaluate the possible role of bile acids excreted with the urine for tumor development, total plasma bile acid concentration and 24 hours urinary bile acid excretion were measured radioimmunologically in rats with total and modified shunts. Additionally the renal 14C-glycocholic acid excretion into the urine was studied after oral administration. Total plasma BA increased from 4.89 +/- 1.0 mumol/l in sham-operated controls to 77.7 +/- 39 mumol/h in PCA and 52.9 +/- 36.7 mumol/l in mPCA rats (p less than 0.001 vs controls, PCA vs mPCA = n.s.). Urinary bile acid excretion rose from 0.2 +/- 0.29 mumol/24 hours in controls to 4.47 +/- 4.49 in PCA and 2.55 +/- 2.22 mumol/24 hours in mPCA rats (p less than 0.001 vs control; PCA vs mPCA = n.s.) 14C-glycocholic acid was excreted within 24 hours into the urine in 13.6 +/- 11.5% in PCA and 26.3 +/- 23.5% of the administered dose in mPCA-rats (controls; 2.98 +/- 0.67%, p less than 0.001; PCA vs mPCA = n.s.). Since renal BA-excretion is similar in both shunted groups, urinary BA does not seem to be of primary significance for cancer development in the urinary tract of totally shunted rats.

[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.

In vitro biosynthesis of the C-glycosidic bond in aloin.

Biosynthetic studies with cell-free extracts from Aloe arborescens Mill. demonstrate the transfer of the glucose moiety from UDP-glucose to aloe emodin anthrone, forming the C-glycosidic linkage in the anthracene derivative aloin. The pH-dependence and the specificity of UDP-glucose and aloe emodin anthrone for the biosynthesis of the C-glycosidic bond in aloin are shown.

L-Ascorbic-acid biosynthesis in the euryhaline diatom Cyclotella cryptica.

L-Ascorbic acid (AA) production in cells of Cyclotella cryptica Reimann, Lewin, Guillard (Bacillariophyceae) is enhanced when darkadapted cells are exposed to light.Heterotrophically grown cells incubated with D-[6-(3)H,6-(14)C]glucose and D-[1-(3)H,6-(14)C]glucose (2 h in dark followed by 15 h light) produced labeled AA with significantly different ratios of (3)H and (14)C. Comparisons of labeling patterns in AA and chitin-derived D-glucosamine support a path of conversion in Cyclotella from D-glucose to AA that "inverts" the carbon chain of the sugar. This process resembles similar conversions found in AA-synthesizing animals and species from two other algal classes.

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.

Hepatic blood flow and cardiac output after porta-caval anastomosis in the rat.

Investigations were performed in rats with portacaval anastomosis (PCA) in order to measure hepatic hemodynamics and cardiac output (CO) 3, 6, 14 and 28 days after operation under pentobarbitone anesthesia using the flow fraction distribution method (131I-MAA) of CO. The latter was calculated using Vierordt's principle from blood volume (BV) (125RIHSA-dilution method) and ICG-appearance time (ICG-AT) (ear-densitometry). Even 3 days after PCA CO was increased to 38.7 +/- 5.0 (SD) ml/min/100 g b.w. (normal 23.8), due to an increase of BV from 6.3 +/- 1.4 to 7.5 +/- 0.6 ml/100 g b.w. and a decrease of ICG-AT from 3.6 +/- 0.4 to 2.8 +/- 0.5 s. Arterial hepatic flow fraction of CO increased to 8.7 +/- 2.8% (control: 5.5 +/- 2.4%). Changes could be observed up to day 28. Hepatic blood flow per g liver tended to stabilize but was still decreased at day 28: 1.5 +/- 0.6 ml/min/g liver (control: 2.0 +/- 0.3). The typical hemodynamic changes in human liver cirrhosis can be reproduced by PCA alone. They are considered to be compensatory mechanisms for a reduced portal liver blood flow, which are not found to compensate completely.

Galactosamine- "hepatitis" in rats with different phagocytic activity of liver RES.

Morphological investigations by lightmicroscopy were performed to evaluate the influence of an altered liver RES-function state on the course of Gal-N-hepatitis. There was a good correlation between the biochemical data and the morphological alterations. The simultaneous infusion of Gal-N 1 g/kg b.w. and carbon particles (2.6 mg/100 g b.w) into the portal vein was followed by subtotal necrosis of the liver and Sanarelli-Shwartzmann-phenomenon. Signs of RES-activity were nearly absent. 8 days after pretreatment with carbon, Gal-N application did not produce Gal-N hepatitis; 21 days after carbon infusion the morphological changes normally found after Gal-N application were present. The morphological studies confirm the concept that an altered RES-function state is a very important factor for the development of liver cell necrosis.

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.

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.

[Effects of porto-caval end-to-side-anastomosis on the liver of rats (author's transl)]. / Zur Auswirkung einer portokavalen End-zu Seit-Anastomose auf die Leber der Ratte.

In young rats (n = 117), with a liver weight of 9.9 +/- 1.6 g ("small livers"), the decrease of total liver blood flow was followed by necrosis of liver parenchymal cells in the first two postoperative weeks. These alterations induced by haemodynamic disorders occured since the hepatic artery-although dilated to its maximum--was insufficient to compensate completely for the decrease of the portal hepatic blood flow. In old rats (n = 33) with a liver weight of nearly the double (19.5 +/- 1.9 g; "big livers") the extrem haemodynamic situation after PCA with a more less sufficient arterial hepatic blood supply was followed by complete liver necrosis including necrosis of the v. Kupffer cells. Rats having survived the PCA-operation showed liver cell necrosis in a more less degree as opposed to the early changes. These changes were not thought to be due to persisting haemodynamic disorders but due to endotoxaemia as found in 85% of the animals by means of the Limulus Gelation Test.