LAXS Studies

Although X-ray and neutron diffraction and scattering methods give only approximate estimates of hydration numbers they can provide precise measures of ion-water distances in solution. In calcium chloride and bromide solutions of various concentrations, Ca-0 distances of between 2.40 and 2.44 A have been reported (167,168,171,172) Ca-0 — 2.26A was claimed in an early X-ray investigation of molar calcium nitrate solution (167,186). EXAFS and LAXS studies showed a broad and asymmetric distribution of Ca-0 distances centered on a mean value of 2.46 A (174). 

O-donor environments with different coordination numbers (Figure 61). Bismuth L edge EXAFS and LAXS studies" of strongly acidic aqueous solutions of Bi were consistent with [Bi(H20)s] data were also reported for bismuth triflate solutions in various liquid organic... 

Mitsubishi-Kagaku Foods Corporation Study of sucrose esters of fatty acids laxative study of S-1170. Unpublished report dated March 29, 1996. (Submitted to JECFA by Mitsubishi Chemical Corporation, Tokyo, Japan). 

Ag(py)4]ta04l T48] Dissolution of AgC104 in py. Compound generated in situ. LAXS study has been reported [T48]. X-ray structure of [Ag(py)4][C104] has been reported [T5]. 

AgOJMSOWraOd [T49] Addition of excess DMSO to a solution of AgC104 in Me2CO followed by solvent removal in vacuo [T49]. X-ray structure and a LAXS study in DMSO solution have been reported [T49]. Warning the compound is explosive [T50J. 

Ag(MeCN)4lX[T52] X = N03,a04 Dissolution of AgX in MeCN. Nitrate complex present in solution at concentrations of less than 4M [T52]. X-ray structure of [Ag(MeCN)4lia04] [T53] and LAXS studies [T54] have been reported. 

Zn(DMSO)tJ[a04]2 n = 4 [TIO], 6 [TIO - T12, T49] Reaction of ZnfQOda with an excess of DMSO [Til] or a mixture of DMSO with Mc2CO [T49] followed by removal of solvent in vacuo or crystallization of the complex at -20 °C [T49]. Method [Til] not recommended, see [T49]. Compound recrystallized from DMSO [T12]. X-ray structure and LAXS studies of [Zn(DMS0)6][C104]2 have been reported all DMSO ligands are O-bonded [T92]. 

Finally, an intriguing possible future therapy arises from a radical idea of Horrobin (2001) that schizophrenia is a nutritional disorder linked to a decreased intake of essential polyunsaturated fatty acids. Recent 31P-MRS studies have shown changes in plasma membrane phospholipids in the neocortex of unmedicated schizophrenics, which would have deleterious consequences on synaptic neurotransmission (Fukuzako, 2001). A clinical trial with the co6 fatty acid derivative ethyleicosa-pentaenoic acid (LAX-101) in patients who had been unresponsive to clozapine, reported that a daily dose of 2g LAX-101 gave a 26% improvement in symptoms over 12 weeks compared with 6% with placebo (Peet and Horrobin, 2001). Maybe in... 

In principle, the same rules hold true when zeolitic alkylation catalysts are used. A detailed study of the influence of PO and OSV on the performance of zeolite H-BEA in a backmix reactor was reported by de Jong et al. (80). The authors developed a simple model of the kinetics, which predicted catalyst lifetimes as a function of P/O and OSV. Catalyst lifetime (which is equivalent to the catalyst productivity, the reciprocal of acid consumption) increased with increasing P/O ratio and decreasing OSV. Furthermore, the authors persuasively demonstrated the superiority of a backmix reactor over a plug flow reactor. Qualitatively similar results were obtained by Taylor and Sherwood (222) employing a USY zeolite catalyst in a backmix reactor. The authors stressed the detrimental effect of unreacted alkene on the catalyst lifetime and product quality. Feller et al. (89) tested LaX zeolites in a backmix reactor and found the catalyst productivity to be nearly independent of the OSV within the examined OSV range. At higher values of OSV, the catalyst life was shorter, but in this shorter time the same total amount of product was produced. The P/O ratio had only a moderate influence on the catalyst performance. 

As bulk sweeteners have not specified ADI values, a similar range of intake studies is not available, and laxative properties more or less exclude excessive intake. 

Laxative effect. Seed hull, taken orally by adults at a dose of 7 g/person, increased weekly fecal mass without influencing transit time or frequency . Seedcoat, administered orally to 80 patients at a dose of 6.4 g/person three times daily, was active in a blinded placebo controlled study of efficacy of extract in treatment of irritable bowel syndrome " . Water extract of the dried kernel, administered orally to 40-year-old adults of both sexes, was active . Seed powder, administered orally to adults of both sexes, was active. Biological activity reported has been patented ". Dried seeds, administered orally to adults at a dose of 0.5 g/person, were active. Placing the seeds in water increased their volume, 90% alcohol produced a decrease in volume to normal seed size, and linseed oil had no effect on volume. The seed mucilage remained in gel form and is considered preferable to the solid form because it is more easily digested " . Dried seed powder, administered orally to 35 patients with chronic constipation at a dose of 50 mg/person, was active in a controlled, double-blind study " . Fiber, administered orally to adults, was active. Psyllium fiber and sennosides were prepared into a wafer to be... 

Long-term follow-up research has shown that about one-fourth of AN patients will recover and the rest will have either partial or no improvement. Mortality rates at 10 years are 6.6% and at 30 years are 18%-20% after presentation for treatment (Theander, 1985 Eckert et ah, 1995). Most follow-up studies of AN show patients with an earlier age onset (under age 18) to have a better chance of recovery. Purging behavior, self-induced vomiting, and laxative abuse are usually predictive of a worse outcome (Eckert et ah, 1995). 

These are among the most powerful, but prolonged use can aggravate constipation. Mechanisms of action are muitipie and not well studied. They include increased permeability of the mucosa leading to accumuiation of water in the lumen, inhibition of intestinal Na+,K-i-ATPase, and increased synthesis of prostagiandins and cAMP. Stimulant laxatives include the following. 

Aloe, senna, and cascara occur naturally in plants. These laxatives are poorly absorbed and after hydrolysis in the colon, produce a bowel movement in 6-12 hours when given orally and within 2 hours when given rectally. Chronic use leads to a characteristic brown pigmentation of the colon known as melanosis coli. There has been some concern that these agents may be carcinogenic, but epidemiologic studies do not suggest a relation to colorectal cancer. 

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