Additional NaCl Research Articles

Decreased capacity for sodium export out of Arabidopsis chloroplasts impairs salt tolerance, photosynthesis and plant performance

Salt stress is a widespread phenomenon, limiting plant performance in large areas around the world. Although various types of plant sodium/proton antiporters have been characterized, the physiological function of NHD1 from Arabidopsis thaliana has not been elucidated in detail so far. Here we report that the NHD1-GFP fusion protein localizes to the chloroplast envelope. Heterologous expression of AtNHD1 was sufficient to complement a salt-sensitive Escherichia coli mutant lacking its endogenous sodium/proton exchangers. Transport competence of NHD1 was confirmed using recombinant, highly purified carrier protein reconstituted into proteoliposomes, proving Na(+) /H(+) antiport. In planta NHD1 expression was found to be highest in mature and senescent leaves but was not induced by sodium chloride application. When compared to wild-type controls, nhd1 T-DNA insertion mutants showed decreased biomasses and lower chlorophyll levels after sodium feeding. Interestingly, if grown on sand and supplemented with high sodium chloride, nhd1 mutants exhibited leaf tissue Na(+) levels similar to those of wild-type plants, but the Na(+) content of chloroplasts increased significantly. These high sodium levels in mutant chloroplasts resulted in markedly impaired photosynthetic performance as revealed by a lower quantum yield of photosystem II and increased non-photochemical quenching. Moreover, high Na(+) levels might hamper activity of the plastidic bile acid/sodium symporter family protein 2 (BASS2). The resulting pyruvate deficiency might cause the observed decreased phenylalanine levels in the nhd1 mutants due to lack of precursors.

Characterization of Chlorococcum pamirum as a potential biodiesel feedstock.

To evaluate the potential of Chlorococcum pamirum for producing biodiesel, the effects of nitrogen, phosphate, initial cell concentrations and NaCl on lipid accumulation and growth were studied. The highest specific growth rate (μ(max)), biomass productivity and lipid content achieved was 1.888 d(-1), 350.1 mg L(-1) day(-1), and 64.9%, respectively. Under nitrogen-deficient condition, the cells accumulated lipids faster at low initial cell concentration. Additional NaCl to nitrogen-deficient media accelerated the lipid accumulation. When adding 10 g L(-1) NaCl to nitrogen-deficient media, the lipid content and productivity of cells cultured outdoors with high initial cell concentration increased from 38.2% and 153 mg L(-1) day(-1) to 54.3% and 192 mg L(-1) day(-1) respectively. Moreover, NaCl enhanced the saturated fatty acids content from 56.40% to 73.41% of total fatty acids. The results show that C. pamirum is a promising organism for biofuel production.

Effect of apical hyperosmotic sodium challenge and amiloride on sodium transport in human bronchial epithelial cells from cystic fibrosis donors

Hypertonic saline (HS) inhalation therapy benefits cystic fibrosis (CF) patients [Donaldson SH, Bennet WD, Zeman KL, Knowles MR, Tarran R, Boucher RC. N Engl J Med 354: 241-250, 2006; Elkins MR, Robinson M, Rose BR, Harbour C, Moriarty CP, Marks GB, Belousova EG, Xuan W, Bye PT; the National Hypertonic Saline in Cystic Fibrosis (NHSCF) Study Group. N Engl J Med 354: 229-240, 2006]. Surprisingly, these benefits are long-lasting and are diminished by the epithelial Na(+) channel blocker amiloride (Donaldson SH, Bennet WD, Zeman KL, Knowles MR, Tarran R, Boucher RC. N Engl J Med 354: 241-250, 2006). Our aim was to explain these effects. Human bronchial epithelial (hBE) cells from CF lungs were grown in inserts and were used in three experimental approaches: 1) Ussing chambers to measure amiloride-sensitive short-circuit currents (INa); 2) continuous perfusion Ussing chambers; and 3) near "thin-film" conditions in which the airway surface of the inserts was exposed to a small volume (30 μl) of isosmotic or HS solution as the inserts were kept in their incubation tray and were subsequently used to measure INa under isosmotic conditions (near thin-film experiments; Tarran R, Boucher RC. Methods Mol Med 70: 479-492, 2002). HS solutions (660 mosmol/kgH2O) were prepared by adding additional NaCl to the isosmotic buffer. The transepithelial short-circuit current (ISC), conductance (GT), and capacitance (CT) were measured by transepithelial impedance analysis (Danahay H, Atherton HC, Jackson AD, Kreindler JL, Poll CT, Bridges RJ. Am J Physiol Lung Cell Mol Physiol 290: L558-L569, 2006; Singh AK, Singh S, Devor DC, Frizzell RA, van Driessche W, Bridges RJ. Methods Mol Med 70: 129-142, 2002). Exposure to apical HS inhibited INa, GT, and CT. The INa inhibition required 60 min of reexposure to the isosmotic solution to recover 75%. The time of exposure to HS required to inhibit INa was <2.5 min. Under near thin-film conditions, apical exposure to HS inhibited INa, but as osmotically driven water moved to the apical surface, the aqueous apical volume increased, leading to an amiloride-insensitive decrease in its osmolality and to recovery of INa that lagged behind the osmotic recovery. Amiloride significantly accelerated the recovery of INa following exposure to HS. Our conclusions are that exposure to HS inhibits hBE INa and that amiloride diminishes this effect.

Accumulation and distribution of Zn in the shoots and reproductive structures of the halophyte plant species Kosteletzkya virginica as a function of salinity

Kosteletzkya virginica is a wetland halophyte that is a good candidate for rehabilitation of degraded salt marshes and production of oil as biodiesel. Salt marshes are frequently contaminated by heavy metals. The distribution of Zn in vegetative and reproductive organs of adult plants, and the NaCl influence on this distribution remain unknown and were thus explored in the present study. Plants were cultivated in a nutrient film technique system, from seedling stage until seed maturation in a control, Zn (100μM), NaCl (50mM) or Zn+NaCl medium. Photosynthesis, ion nutrition, malondialdehyde and non-protein thiol concentrations were quantified. Zinc distribution in reproductive organs was estimated by a laser ablation-inductively coupled plasma-mass spectrometry procedure (LA-ICP-MS). Adult plants accumulated up to 2mgg(-1) DW Zn in the shoots. Zinc reduced plant growth, inhibited photosynthesis and reduced seed yield. Zinc accumulation in the seeds was only two times higher in Zn-treated plants than in controls. Exogenous NaCl neutralized the damaging action of Zn and modified the Zn distribution through a preferential accumulation of toxic ions in older leaves. Zinc was present in seed testa, endosperm and, to a lower extent, in embryo. Additional NaCl induced a chalazal retention of Zn during seed maturation and reduced final Zn seed content. It is concluded that NaCl 50mM had a positive impact on the response of K. virginica to Zn toxicity and acts through a modification in Zn distribution rather than a decrease in Zn absorption.

Mucilaginibacter ginsenosidivorax sp. nov., with ginsenoside converting activity isolated from sediment

A Gram-reaction-negative, strictly aerobic, non-motile, non-spore-forming, and rod-shaped bacterial strain designated KHI28(T) was isolated from sediment in Gapcheon (river) and its taxonomic position was investigated using a polyphasic approach. Strain KHI28(T) grew at 10-42°C and at pH 5.5-8.5 on R2A and nutrient agar without additional NaCl as a supplement. Strain KHI28(T) possessed β-glucosidase activity, which was responsible for its ability to transform ginsenosides Rb1 and Re (ones of the dominant active components of ginseng) to C-K and Rg2, respectively. On the basis of 16S rRNA gene sequence similarity, strain KHI28(T) was shown to belong to the family Sphingobacteriaceae and to be related to Mucilaginibacter dorajii DR-f4(T) (97.9% sequence similarity), M. polysacchareus DRP28(T) (97.3%), and M. lappiensis ANJLI2(T) (97.2%). The G+C content of the genomic DNA was 45.8%. The predominant respiratory quinone was MK-7 and the major fatty acids were summed feature 3 (comprising C16:1 ω6c and/or C16:1 ω7c), iso-C15:0 and C16:0. DNA and chemotaxonomic data supported the affiliation of strain KHI28(T) to the genus Mucilaginibacter. Strain KHI28(T) could be differentiated genotypically and phenotypically from the recognized species of the genus Mucilaginibacter. The isolate therefore represents a novel species, for which the name Mucilaginibacter ginsenosidivorax sp. nov. is proposed, with the type strain KHI28(T) (=KACC 14955(T) =LMG 25804(T)).

Effect of NaCl on growth and Cd accumulation of halophyte Spartina alterniflora under CdCl2 stress

A study quantifying the effect of NaCl on growth and Cd accumulation of Spartina alterniflora subjected to Cd stress was conducted. Seedlings were cultivated in the presence of 1 or 3mM Cd alone, or combined with NaCl (50 or 100mM). The results showed that NaCl magnified the phytotoxicity of moderate Cd stress (1mM Cd) on plants due to reduced levels of plant biomass, plant height, and chlorophyll a+b, while no synergistic effects were recorded under severe Cd stress (3mM Cd). Proline and Ca2+ accumulated along with additional NaCl under moderate Cd stress, instead of reduced or unchanged levels under severe Cd stress owing to different adoption strategies caused by NaCl under different Cd stresses. NaCl reduced the oxidative stress in Cd-treated plants through increasing levels of antioxidative enzymes (catalase (CAT) and peroxidase (POD)) under moderate Cd stress. With NaCl addition, Cd2+ contents in S. alterniflora increased and reduced under moderate and severe Cd stress, respectively. However, total Cd2+ amounts increased with increasing NaCl concentration due to biological dilution. NaCl improved the increase of Cd2+ translocation factor (TF) under moderate Cd stress, indicating that NaCl might improve Cd2+ uptake and translocation from roots to shoots, and enhance the phytoextraction of S. alterniflora on Cd; while phytostabilization of Cd under severe Cd stress may be possible due to the reduced TF. Thus, NaCl alleviated phytotoxicity caused by Cd stress through improved management of osmotic solutes and oxidative status, and affected Cd accumulations in S. alterniflora differently under moderate and severe Cd stresses.

Effects of dietary salt restriction on puromycin aminonucleoside nephrosis

Dietary salt restriction may reduce proteinuria although the mechanism is not clear. We investigated the effects of dietary salt restriction on rat kidneys in an animal model of glomerular proteinuria. Male Sprague-Dawley rats were divided into 3 groups: vehicle-treated normal-salt controls, puromycin aminonucleoside (PA)-treated normal-salt rats, and PA-treated low-salt rats. PA was given at a dose of 150 mg/kg BW at time 0, followed by 50 mg/kg BW on days 28, 35, and 42. Sodium-deficient rodent diet with and without additional NaCl (0.5%) were provided for normal-salt rats and low-salt rats, respectively. On day 63, kidneys were harvested for histopathologic examination. PA treatment produced overt proteinuria and renal damage. Dietary salt restriction insignificantly reduced proteinuria in PA-treated rats, and PA-treated low-salt rats had lower urine output and smaller creatinine clearance than vehicle-treated normal-salt controls. The tubulointerstitial injury score positively correlated with proteinuria. It was significantly increased by PA treatment and relieved by low-salt diet. ED1-positive infiltrating cells and immunostaining for interstitial collagen III were significantly increased by PA treatment. These changes appeared less in PA-treated low-salt rats although the differences in PA-treated normal-salt versus low-salt rats did not reach the statistical significance. Our results suggest that renal histopathology in PA nephrosis may potentially be improved by dietary salt restriction. The decreasing tendency in glomerular filtration rate induced by low-sodium diet might be beneficial in retarding renal progression.

Sodium chloride improves photosynthesis and water status in the succulent xerophyte Zygophyllum xanthoxylum

Zygophyllum xanthoxylum, a C(3) woody species, is a succulent xerophyte that is well adapted to arid environments. Our previous investigations showed that Na(+) has a positive effect on the growth of Z. xanthoxylum under drought conditions, which was closely related to high Na(+) accumulation in leaves. To reveal the physiological mechanisms underlying how Na(+) accumulation improves the drought resistance of Z. xanthoxylum, 3-week-old seedlings were treated with a series of additional external NaCl concentrations (5-150 mM) in sand culture experiments. Seedlings were also subjected to water deficit (30% of field water capacity) in the presence or absence of additional NaCl (50 mM) in pot experiments. The results indicated that 50 mM NaCl could mitigate deleterious impacts of water deficit on the growth of Z. xanthoxylum, by improving the relative water content, inducing a significant drop in leaf water potential and, concomitantly, increasing leaf turgor pressure and chlorophyll concentrations resulting in an enhancement of overall plant photosynthetic activity (i.e., photosynthetic rate and water use efficiency). Furthermore, NaCl (50 mM) could alleviate the inhibitory effect of water deficit on the activity of photosystem II in Z. xanthoxylum. The contribution of Na(+) to the total osmotic potential varied from 8% in the control to 13% in plants subjected to water deficit and, surprisingly, to 28% in plants grown in the presence of 50 mM NaCl under water deficit; however, the contribution of K(+) significantly decreased from 13 to 8%. These findings suggest that, under arid environments, Z.xanthoxylum is able to accumulate a high concentration of Na(+) in its leaves and use it directly for osmotic adjustment, which was coupled with an improvement in leaf hydration and photosynthetic activity.

Local modification of NaCl thin films on Cu(111) under different bias voltages

The local modification of NaCl thin films on Cu(111) under different bias voltages is investigated using a scanning tunneling microscope (STM) at room temperature. We find that the type of modification of NaCl thin films is dependent on sample bias voltage ( V s). Defects in a triple-layer-thick NaCl film are destabilized and repelled away from the region beneath an STM tip by applying V s in the range of 0.3 V ≤ | V s| ≤ 0.5 V. When V s is larger than + 1.2 V or smaller than − 4.0 V, the removal of NaCl films takes place and a bare Cu surface appears. In this case, the removed NaCl is transferred to the STM tip and can be supplied back to the surface from the STM tip. The redeposition of NaCl enables not only the reformation of single-crystalline NaCl films on a bare Cu surface but also the formation of additional NaCl films on a clean NaCl film surface.

Impact of sodium chloride on wheat flour dough for yeast‐leavened products. II. Baking quality parameters and their relationship

The traditional use of sodium chloride (NaCl) fulfills various important rheological, technological and sensory properties in the manufacturing of yeast-leavened products. However, the use of NaCl in food production has been discussed controversially since a high intake of sodium seems to be associated with hypertension. This study investigates the baking quality parameters of wheat breads containing various levels of NaCl (0-40 g NaCl kg(-1) flour). Crumb firmness and rate of bread staling decreased with decreasing NaCl levels. A slight increase in loaf volume was observed based on the increased yeast leavening ability resulting from additional NaCl. Higher crumb retrogradation (measured by differential scanning calorimetry) was observed with low NaCl levels. The retrogradation effect is based on the theory that NaCl probably leads to Na(+) inclusion in starch molecules during storage and thus reduces retrogradation. Further, significant (P⩽0.05) linear relationships (r ≥ 0.829) between Rheofermentometer results, bread volume and crumb firmness were found, suggesting a predictability of bread quality by measurement of gas release.

Experimental study about the agglomeration behavior in slurry prepared by adding excess polyelectrolyte dispersant

In our previous paper we found that the particles in the slurry can agglomerate by adding larger amount of polyelectrolyte dispersant compared to that needed to attain well dispersion. Thus, the dependency of initial particle concentration on the agglomeration and its mechanism in slurry prepared by adding excess polyelectrolytes was experimentally discussed. It was shown that agglomeration behavior strongly depends on the additive amount of polyelectrolytes, not on the polyelectrolyte concentration in the solution. It was also found that the dominant factor of agglomeration in slurry prepared by adding extra polyelectrolytes should be the compression of the electrical double layer by the increased counter ion concentration, not by the so called depletion effect or by pH change. Interestingly, the final sediment had a relatively high packing fraction and good flowability in the case of the agglomerated slurry with extra polyelectrolytes compared to that of the agglomerated slurry with an additional NaCl solution.

Swarming motility by Photorhabdus temperata is influenced by environmental conditions and uses the same flagella as that used in swimming motilityThis is scientific contribution No. 2431 from the New Hampshire Agricultural Experiment Station.

Photorhabdus temperata, an insect pathogen and nematode symbiont, is motile in liquid medium by swimming. We found that P.temperata was capable of surface movement, termed swarming behavior. Several lines of evidence indicate that P. temperata use the same flagella for both swimming and swarming motility. Both motility types required additional NaCl or KCl in the medium and had peritrichous flagella, which were composed of the same flagellin as detected by immunoblotting experiments. Mutants defective in flagellar structural proteins were nonmotile for both motility types. Unlike swimming, we observed swarming behavior to be a social form of movement in which the cells coordinately formed intricate channels covering a surface. The constituents of the swarm media affected motility. Swarming was optimal on low agar concentrations; as agar concentrations increased, swarm ring diameters decreased.

Effects of Dietary Salt Restriction on Puromycin Aminonucleoside Nephrosis: Preliminary Data

Proteinuria is a major promoter that induces tubulointerstitial injury in glomerulopathy. Dietary salt restriction may reduce proteinuria, although the mechanism is not clear. We investigated the effects of dietary salt restriction on rat kidneys in an animal model of glomerular proteinuria. Male Sprague-Dawley rats were used and divided into 3 groups: vehicle-treated normal-salt controls, puromycin aminonucleoside (PA)-treated normal-salt rats, and PA-treated low-salt rats. PA was given at a dose of 150 mg/kg BW at time 0, followed by 50 mg/kg BW on days 28, 35, and 42. Sodium-deficient rodent diet with and without additional NaCl (0.5%) were provided for normal-salt rats and low-salt rats, respectively. On day 63, kidneys were harvested for histopathologic examination and immunohistochemistry. PA treatment produced overt proteinuria and renal damage. Dietary salt restriction insignificantly reduced proteinuria in PA-treated rats, and PA-treated low-salt rats had lower urine output and lower creatinine clearance than vehicle-treated normal-salt controls. When tubulointerstitial injury was semiquantitatively evaluated, it had a positive correlation with proteinuria. The tubulointerstitial injury score was significantly increased by PA treatment and relieved by low-salt diet. ED1-positive infiltrating cells and immunostaining for interstitial collagen III were significantly increased by PA treatment. These changes appeared to be less common in PA-treated low-salt rats, although the differences in PA-treated normal-salt versus low-salt rats did not reach statistical significance. Our results suggest that renal histopathology in PA nephrosis may potentially be improved by dietary salt restriction. Non-hemodynamic mechanisms induced by low-sodium diet might contribute to renoprotection.

Phosphate adsorption from aqueous solutions by disused adsorbents: Chitosan hydrogel beads after the removal of copper(II)

The traditional treatment for disused adsorbents is usually recovery for recycling or direct discarding. In this paper, a more efficient and economical method is introduced to treat disused adsorbents. Chitosan hydrogel beads (CS) are proven to be effective biosorbents for the removal of many heavy metal ions from aqueous solutions. The CS after the saturated adsorption of metal ions are usually recovered in dilute acidic solutions. However, in this work, the disused CS after the removal of copper(II) (Cu(II)) were not recovered but were directly applied to adsorb phosphate from the aqueous solutions. The CS after the adsorption of Cu(II) were stable and suitable for phosphate adsorption within a wide pH range. The results of pH effects on the adsorption capacities of phosphate indicated that the maximum was achieved at around pH 5.0 near 28.86mgP/g. In the various forms of phosphates, the Cu(II)-loaded CS preferred to adsorb dihydrogen phosphate. Further adsorption equilibrium and kinetics study showed that the adsorption behaviors were mainly ascribed to chemical adsorption. The adsorption isotherm was well described by the Langmuir equation. The adsorption kinetics followed both pseudo first-order and second-order models. The effects of electrolytes on the adsorption of phosphate indicated that the additional NaCl and Na2SO4 both slightly decreased the adsorption capacities for the anions’ competition of adsorption active sites.

Zwei strukturverwandte Oxidnitridchalkogenide der Lanthanoide: Tb3ONSe2 und La5O2NS4

AbstractThe structurally related oxide nitride chalcogenides Tb3ONSe2 and La5O2NS4 can be prepared by the oxidation of the respective lanthanoid metal (M = Tb and La) with selenium or sulfur and sodium azide (NaN3) in the presence of oxygen‐containing impurities, when iodine (I2) or the corresponding lanthanoid trichloride (MCl3) is used as sodium trap for the formation of NaI or NaCl, respectively. The thermal treatment of these mixtures along with additional NaI or NaCl as flux at 900 °C in evacuated silica tubes yielded transparent, yellow polyhedra in the case of Tb3ONSe2 or orange, lath‐shaped crystals of La5O2NS4. Both monoclinic structures (C2/m, Z = 4) were determined from X‐ray single‐crystal diffraction data (Tb3ONSe2: a = 1548.85(9), b = 392.02(2), c = 968.61(6) pm, β = 97.194(3)°; La5O2NS4: a = 1571.13(8), b = 409.67(2), c = 1681.03(9) pm, β = 101.204(3)°). The crystal structure of Tb3ONSe2 comprises three crystallographically different Tb3+ cations residing in six‐ and sevenfold coordination of the respective anions, whereas the crystal structure of La5O2NS4 shows five different La3+ cations with coordination numbers from six to eight. For the first time in the chemistry of oxide nitride chalcogenides of the lanthanides, an ordering of the light anions (O2– and N3–) is observed, and proper structure descriptions based on vertex‐ and edge‐connected [OM4]10+ and [NM4]9+ tetrahedra (M = Tb and La) becomes possible. As main structural feature, a bulky chain {}^1_\infty{[ONTb3]4+} running along [010] can be detected in the crystal structure of Tb3ONSe2. The same morphology, but a different chemistry is realized in the related crystal structure of La5O2NS4, where these topologically equivalent strands {}^1_\infty{[O2La3]5+} and an additional second chain {}^1_\infty{[NLa2]3+}, built up by vertex‐ and edge connected [NLa4]9+ tetrahedra, compose the compound. As supporting tool for the distinction of the O2– and N3– anions in both crystal structures, the valence‐bond concept is also applied.

Water uptake, water use efficiency, plant growth and ionic balance of wheat, barley, canola and chickpea plants on a sodic vertosol with variable subsoil NaCl salinity

Abstract Salinity in topsoil and subsoil is one of the major abiotic environmental stresses to crop production. To investigate the comparative tolerance ability of wheat, barley, canola and chickpea to subsoil NaCl salinity and its impact on water uptake, water use efficiency, plant growth and ionic balance, a pot experiment was conducted on a heavy texture soil (sodic vertosol) having 20 ESP (exchangeable sodium percentage), 3.5 dS/m EC e and 400 mg/kg Cl with additional NaCl applied in subsoil at 500, 1000, 1500 and 2000 mg/kg soil. Plants were harvested 40 days after sowing and assessed for different parameters. Increasing levels of subsoil NaCl salinity had significant depressing effect on shoot and root biomass, root/shoot ratio, water uptake and water use efficiency (shoot biomass production with a unit amount of applied water), leaves K:Na ratio and Ca:Na ratio of all the four species, but the magnitude of effect varied considerably among the species. Chickpea was affected most followed by wheat, barley and canola at the highest level of subsoil NaCl salinity. There was 64%, 49%, 37% and 34% reduction in shoot dry weight of chickpea, wheat, barley and canola respectively by highest subsoil salinity. Similarly water uptake declined by 61%, 36%, 31% and 26% respectively in chickpea, wheat, barley and canola. Water use efficiency of four species was in order of barley > canola > wheat > chickpeas on this sodic vertosol. The cumulative effects of reduced osmotic potential of soil solution, ion toxicity (high concentrations of Cl and Na) in soil/plants and ionic imbalance (reduced K:Na and Ca:Na ratio) within plant system under increased subsoil NaCl salinity contributed to reduce water uptake and plant growth in all the four crops, and the effects were more severe in chickpeas. Wheat despite having considerably lower Na and Cl in their leaves suffered greatly in plant growth and water uptake compared with barley and canola indicating better tolerance ability of barley and canola to high Cl and Na build up at tissue level. Results suggest chickpea to be the most sensitive to subsoil NaCl salinity. The growing of comparatively tolerant species like barley and canola may be the better option for sustaining crop production and higher water use efficiency on sodic vertosols with high subsoil NaCl salinity.

Effects of Salt Supplementation on the Albuminuric Response to Telmisartan With or Without Hydrochlorothiazide Therapy in Hypertensive Patients With Type 2 Diabetes Are Modulated by Habitual Dietary Salt Intake

OBJECTIVEThis prospective randomized double-blind placebo-controlled crossover study examined the effects of sodium chloride (NaCl) supplementation on the antialbuminuric action of telmisartan with or without hydrochlorothiazide (HCT) in hypertensive patients with type 2 diabetes, increased albumin excretion rate (AER), and habitual low dietary salt intake (LDS; <100 mmol sodium/24 h on two of three consecutive occasions) or high dietary salt intake (HDS; >200 mmol sodium/24 h on two of three consecutive occasions).RESEARCH DESIGN AND METHODSFollowing a washout period, subjects (n = 32) received 40 mg/day telmisartan for 4 weeks followed by 40 mg telmisartan plus 12.5 mg/day HCT for 4 weeks. For the last 2 weeks of each treatment period, patients received either 100 mmol/day NaCl or placebo capsules. After a second washout, the regimen was repeated with supplements in reverse order. AER and ambulatory blood pressure were measured at weeks 0, 4, 8, 14, 18, and 22.RESULTSIn LDS, NaCl supplementation reduced the anti-albuminuric effect of telmisartan with or without HCT from 42.3% (placebo) to 9.5% (P = 0.004). By contrast, in HDS, NaCl supplementation did not reduce the AER response to telmisartan with or without HCT (placebo 30.9%, NaCl 28.1%, P = 0.7). Changes in AER were independent of changes in blood pressure.CONCLUSIONSThe AER response to telmisartan with or without HCT under habitual low salt intake can be blunted by NaCl supplementation. By contrast, when there is already a suppressed renin angiotensin aldosterone system under habitual high dietary salt intake, the additional NaCl does not alter the AER response.

43 COMPARISON OF THE EFFECTS OF PRE-TREATMENT WITH SODIUM CHLORIDE, SUCROSE AND TREHALOSE ON DEVELOPMENTAL COMPETENCE OF PORCINE OOCYTES

Modified environmental stress was reported to improve the developmental competence and cryotolerance of porcine oocytes, such as high hydrostatic pressure (HHP; Du et al. 2008 Cloning Stem Cells, Epub ahead of print) and osmotic stress (Lin et al. 2008 Reprod. Biomed. Online, in press). HHP also improved the cryotolerance of bovine and murine blastocysts (Pribenszky et al. 2005a Reprod. Dom. Anim. 40, 338–344; Pribenszky et al. 2005b Anim. Reprod. Sci. 87, 143–150). In the present study we compared the effects of NaCl with that of concentrated solutions of two non-permeable osmotic agents, sucrose and trehalose on in vitro maturated oocytes. A total of 2050 slaughterhouse-derived porcine cumulus–oocyte complexes (COCs) were matured for 41–42 h, and then put into 800 μL T2 (HEPES-buffered TCM-199 [Earle’s salts] with 2% cattle serum) supplemented with additional NaCl, sucrose or trehalose with the same osmotic level (588 mOsmol) in 4-well dishes and incubated for 1 h at 38.5°C in air. COCs incubated in T2 under the same conditions without supplementation were used as controls. Subsequently COCs were incubated in IVM medium for 1 h at 38.5°C in 5% CO2 with maximum humidity. After this recovery period cumulus cells were removed with 1 mg mL–1 hyaluronidase and pipetting, and oocytes were used as recipients for somatic nuclear transfer with handmade cloning (HMC) method. Porcine fetal fibroblasts were used as nuclear donor cells. Embryo culture was performed in PZM-3 medium (Yoshioka et al. 2002 Biol. Reprod. 66, 112–119) in 5% CO2, 5% O2 and 90% N2 and maximum humidity. Cleavage and blastocyst rates were checked on Day 1 and Day 6, respectively. Cell numbers were counted after fixation in glycerol containing 20 μg mL–1 Hoechst 33342 fluorochrome on Day 6. t-test was performed for statistical calculations with SPSS 11.0 program (SPSS, Chicago, IL, USA). Results are shown in Table 1. Osmotic stress with both permeable and non-permeable agents increased developmental competence of porcine IVM oocytes. NaCl seems to be more appropriate for the purpose, as the other two components resulted in decreased cell number in blastocysts after somatic cell nuclear transfer (SCNT). In conclusion, a simple NaCl pre-treatment of oocytes has improved the in vitro efficiency of porcine SCNT. Table 1.Developmental competence of porcine HMC embryos derived from oocytes treated with different agents The authors thank Ruth Kristensen, Anette Pedersen, Janne Adamsen and Klaus Villemoes for their help and excellent technical assistance.

Die Oxidnitridselenide M3ONSe2 dreiwertiger Lanthanoide (M = Ce – Nd)

AbstractThe Oxide Nitride Selenides M3ONSe2 of Trivalent Lanthanoids (M = Ce – Nd)Oxide nitride selenides of the trivalent lanthanoids (M = Ce – Nd) with the composition M3ONSe2 can be prepared by the oxidation of the respective lanthanoid metal with selenium and sodium azide (NaN3) in presence of impurities containing oxygen when the corresponding lanthanoid trichloride (MCl3) is used as sodium trap for the coformation of NaCl. The thermal treatment of these mixtures along with additional NaCl as flux at 900 °C in evacuated silica tubes secures the formation of fawn, transparent, lath‐shaped crystals. The monoclinic structure (C2/m, Z = 6) was determined from X‐ray single‐crystal diffraction data (Ce3ONSe2: a = 2480.51(14), b = 406.85(3), c = 952.83(6) pm, β = 95.506(4)°; Pr3ONSe2: a = 2462.72(14), b = 403.74(3), c = 947.26(6) pm, β = 95.731(4)°; Nd3ONSe2: a = 2440.35(14), b = 401.48(3), c = 944.02(6) pm, β = 95.763(4)°). Five crystallographically different M3+ cations reside in six‐ to eightfold coordination of the respective anions (three independent O2−/N3− and Se2− each), for which a statistic distribution of the light elements (O2− : N3− = 1 : 1) has to be assumed. However, the main features of the crystal structure are (O2−/N3−)‐centred (M3+)4 tetrahedra. For the first time ever within the same structure of this kind, condensation of these anion‐centred cation polyhedra forming strands and layers simultaneously could be detected. Cis‐edge connected [(O/N)M4]9.5+ tetrahedra build up the chain components $^{1}_{\infty}\rm \{[(O/N)(M4)_{3/3}(M5)_{1/1}]^{3,5+}\}$ running along [010], which are already known as dominating core in some crystal structures of pure nitride chalcogenides (e.g. Sm4N2S3 and Tb4N2Se3). A new motif of condensed tetrahedral units comprises the second feature. By fusing [(O/N)M4]9.5+ tetrahedra via vertices and edges, one‐dimensional strand sections from the cationic sheets $^{2}_{\infty}\rm \{([OC_{4/4}]^{+})_{2}\}$ of the Ce2O2S‐type structure, which are further connected only via common vertices to form a lower‐condensed steplike two‐dimensional layer $^{2}_{\infty}\rm \{[(O/N)_{4}M_{5}]^{5+}\}$, spreading parallel to the (100) plane, emerge for the very first time.

Directing the Growth of Semiconductor Nanocrystals in Aqueous Solution: Role of Electrostatics

In this study, we demonstrate a new insight into the growth stage of aqueous semiconductor nanocrystals (NCs); namely, that the experimental variable-dependent growth rate and photoluminescence quantum yields (PLQYs) are understandable according to electrostatics. In this context, the aqueous NCs possess (from core outwards) an inorganic core, ligand layer, adsorbed layer, and a diffuse layer. The presence of an electric double-layer not only makes the NCs dispersible in the colloidal solution, but also governs the migration of monomers and monomer adsorption on the NC surface. To maintain NC growth, monomers need to migrate through the double-layer. Consequently, the nature of the diffuse layer influences the ability of monomer diffusion and hence the growth rate of NCs. Systematic studies reveal that the experimental variables, including precursor concentrations, pH of the solution, additional NaCl concentrations, ratio of Cd to ligand, and the nature of the ligands significantly govern the nature of the NC electric double-layer. The experimental variables, which reduce the thickness of the diffuse layer, benefit from monomer diffusion and a rapid growth of NCs. However, on the other hand, the diffuse layer also presents a charge-selective transfer of Cd monomers. The neutral monomers, such as the complex of Cd(2+) and 3-mercaptopropionic acid (MPA) with 1:1 molar ratio [Cd(MPA)], migrate through the diffuse layer more easily than the charged ones [Cd(MPA)(2) (2-) or Cd(MPA)(3) (4-)], thus facilitating the growth of NCs. The nature of the adsorbed layer inside the diffuse layer, defined as the assumed interface of solid NCs and the liquid environment, also affects the growth rate and especially the PLQYs of NCs through the adsorption and coalescence of monomers on this interface. Strong interaction between the adsorbed layer and Cd monomers provides the opportunity to accelerate NC growth and to obtain NCs with high PLQYs.