Monoazo dyes for polyamide derived from 4-alkylamido-2-hydroxybenzoic acids

Data on a series of 65 azo dyes derived from 4-alkylamido-2-hydroxybenzoic acids are reported. The dyes are suitable for application to polyamide fibres.Many correlations between the nature of substituents and the physical, spectroscopic or tinctorial properties of dyes were established. Correlations between structure and colour of dyed fabrics were also found.     

Polymerization of some oxiranes using the diphenylzinc-butanone system in benzene at 60°C

The diphenylzinc-butanone system was used as polymerization catalyst for some oxiranes in benzene solution at 60°C. This system is greatly influenced by the molar ratio of butanone to diphenylzinc, and the maximum catalytic activity for propylene oxide and ethylene oxide was found for a ratio of unity. GPC results strongly suggest the presence of more than one active species for the system. ¹³C NMR analysis indicates that the resulting poly(propylene oxide) has a head-to-tail arrangement. For the polymerization of propylene oxide with butanone/diphenylzinc = 1, after an initial induction period, the reaction was first-order with respect to monomer with k = 2·51 × 10^?5 s^?1. Ethylene oxide polymerizations using butanone/diphenylzinc = 1 and 5 were also first-order with respect to monomer after an initial induction period with k = 7·80 × 10^?6 s^?1 and k = 5·71 × 10^?6 s^?1, respectively. The diphenylzinc-butanone system was not an effective catalyst for styrene oxide polymerization.     

Structure and ion dynamics in AgI : Ag2B4O7 vitreous electrolytes

Compounds of the system (AgI)_x(Ag₂B₄O₇)_1?x can be thought of as a network made by an equal number of BO₃ and BO₄ groups containing silver iodide polyhedra. Partially crystalline compounds are obtained when the AgI molar fraction, x, is more than two times the Ag₂B₄O₇ fraction. For the same iodine concentration, the ionic conductivities of the AgI : Ag₂B₄O₇ glasses are comparable with those of other AgI : Ag-oxysalt glasses. However, their glass transition temperatures are substantially higher. With increasing silver iodine content, the physical properties which have been investigated approach smoothly the corresponding values expected for α-AgI. However, it is shown that Ag⁺ within the iodide polyhedra is not the unique current carrier and that a wide distribution of barrier heights exists in these glasses.     

Local diagnostic reference levels in standard X-ray examinations

The national diagnostic reference levels (NDRLs) form an efficient, concise and powerful standard for optimising radiation protection of a patient. However, in a large hospital, where many radiological departments are present, it is also possible to calculate and define lower dose values as local diagnostic reference levels (LDRLs). In our hospital there are eight radiological departments; in each of these, the entrance skin dose (ESD) distributions were determined for 10 standard projections (AP Abdomen, PA and LAT Chest, AP and LAT Lumbar Spine, LAT Lumbo-Sacral Joint, AP Pelvis, PA and LAT Skull and AP Urinary tract) and then the ESDs were compared with data previously published and with Italian NDRLs. All ESD values were below the corresponding NDRLs. The maximum/minimum ratio of ESDs ranged from 3.9 (LAT Skull) to 34.3 (AP Abdomen) for individual adult patients and from 2.1 (PA Skull) to 6.5 (Urinary tract) across the mean values of the radiological departments. Finally, it is shown how LDRLs can be proposed to obtain a more fully optimised radiation protection of patients.     

Reduction of central nervous system reperfusion injury in rabbits using doxycycline treatment

BACKGROUND AND PURPOSE: Activated leukocytes appear to potentiate central nervous system reperfusion injury, and agents that block leukocyte adhesion have shown neuroprotective efficacy in experimental models. Doxycycline, a tetracycline antibiotic, inhibits leukocyte function in vitro, presumably through divalent cation binding. We used a model of focal central nervous system reperfusion injury to determine the efficacy of doxycycline treatment in preserving neurological function. METHODS: Rabbits randomly received 10 mg/kg i.v. doxycycline 30 minutes before ischemia (pretreatment group) or 45 minutes after ischemia (posttreatment group) or received phosphate-buffered saline vehicle (control group) followed by 10 mg/kg q 8 hours times two. The average length of reversible spinal cord ischemia required to produce paraplegia (P50) at 18 hours was calculated for each group. RESULTS: For the control group (n = 13), the P50 was 22.8 +/- 2.2 minutes; for the pretreatment group (n = 14), 35.5 +/- 2.4 minutes (P < .01; t = 3.8); and for the posttreatment group (n = 13), 31.4 +/- 4.2 minutes (not significant; t = 1.6). Doxycycline also attenuated postischemic decreases in vivo leukocyte counts and inhibited in vitro leukocyte adhesion. Therapeutic doxycycline levels at 24 hours were confirmed in the plasma and spinal cord. CONCLUSIONS: This significant protective effect suggests that doxycycline, a safe and readily available agent, may play a role in reducing clinical central nervous system reperfusion injury.     

Synthesis and characterization of P(MMA-AA) copolymers for targeted oral drug delivery

This paper describes the development of pH-sensitive poly(methyl methacrylate-acrylic acid) copolymers for the enteric coating of pharmaceutical products for oral administration. To obtain the dissolution at the desired pH level, different pH-sensitive polymers are available on the market. Usually, for each desired dissolution pH, an ad hoc polymer is designed. Thus, different dissolution pH values could ask for completely different polymers. Instead, the materials proposed in this work are copolymers of the same two monomers, and the different dissolution pH was obtained by changing the volume fraction of the hydrophobic methyl methacrylate monomer to the hydrophilic acrylic acid monomer. Increasing the volumetric percentage of methyl methacrylate causes the polymer to dissolve at increasing pH, until the dissolution does not take place at all, and it is replaced by a slow swelling phenomenon. The copolymers obtained were characterized by differential scanning calorimetry, in order to evaluate their glass transition temperature, and these latter were related to %MMA. The molecular weights of the pure polymers (PAA, PMMA) were measured by intrinsic viscosity, to further validate the glass transition temperatures observed. The dissolution of the copolymers was carefully tested in buffer solutions for a dense set of pH values. A linear relationship between dissolution pH and volumetric percentage of methyl methacrylate was obtained from these measurements. As a result, for any physiological compartment, the copolymer which dissolves at the pH of interest can be easily synthesized.     

Editorial: Industrial relevance of molybdenum in China

About 80% of all molybdenum mined in the world (not including units recovered via recycling) is used as an alloying element in iron and steel. In general, the intensity of molybdenum use in China is still lower than in more highly developed regions such as the USA and Europe. This difference is manifest in both carbon steels and stainless steels, suggesting a significant opportunity for more widespread use of molybdenum in the future as China follows its self-reliance policy, calling for more sophisticated materials. Active market development, as being pursued by the International Molybdenum Association (IMOA), is a key asset in that respect. This article summarizes some key facts on molybdenum mining, use and market development in China.The full text can be downloaded at https://link.springer.com/content/pdf/10.1007%2Fs40436-019-00270-5.pdf     

A methacrylic hyaluronic acid derivative for potential application in oral treatment of celiac disease

Objective: Aim of this work was the synthesis of a methacrylic hyaluronic acid (HA) derivative and the production, via photocrosslinking, of related hydrogels loaded with an endopeptidase intended for a potential oral treatment of celiac disease.

Methods: The methacrylic derivative of HA was prepared through a one-pot procedure involving the reaction with ethylenediamine (EDA) and methacrylic anhydride (MA). The obtained derivative, named HA-EDA-MA, was used to prepare photocrosslinked hydrogels loaded with a prolyl endopeptidase derived from Flavobacterium meningosepticum (PEP FM) able to detoxify gliadin. Obtained hydrogels were recovered as gels or freeze-dried powders.

Results: Hydrogels obtained as freeze-dried powders, are able to protect loaded enzyme from degradation due to freeze-drying process and from alteration during storage, overall in the presence of a cryoprotectant. All photocrosslinked HA-EDA-MA hydrogels (gels and powders) release PEP FM in simulated intestinal fluid in sustained manner and in active form. HA-EDA-MA hydrogels are nontoxic as demonstrated through in vitro studies on BALB 3T3 cells.

Conclusions: Prepared hydrogels show a potential application for oral treatment of celiac disease thanks to the possibility to release enzymes able to detoxify the gliadin peptide that induces the immunogenic response.     

One-year persistence of neutralizing anti-SARS-CoV-2 antibodies in dialysis patients recovered from COVID-19

The immunological mechanisms that modulate immune response to SARS-CoV-2 infection remain elusive. Little is known on the magnitude and the durability of antibody response against COVID-19. There is consensus that patients with immune dysfunction, such as dialysis patients, may be unable to mount a robust and durable humoral immunity after infections. Recent studies showed that dialysis patients seroconverted after COVID-19, but data on the durability of the immune response are missing. We reported the data of a durable anti-spike protein seroconversion after natural SARS-CoV-2 infection in three patients on hemodialysis with a mean age of 67.2 ± 13.8 years. A mean antibody titer of 212.6 ± 174.9 UA/ml (Liaison®, DiaSorin) was found after one year (range, 366–374 days) from the diagnosis of COVID-19. In conclusion, this case series provided evidence that patients receiving hemodialysis who recovered from severe COVID-19 were able to mount a long-lasting immune response against SARS-CoV-2. Although the protective capacity of this long-term immunity remains to be determined, these patients did not report signs of reinfection after recovery from COVID-19.     

The effect of cholesterol supplementation on glutamate-induced hypocholesterolemia in the Mongolian gerbil

The effect of cholesterol supplementation on the hypocholesterolemia induced by glutamic acid feeding has been studied in the Mongolian gerbil. Serum triglycerides and phospholipids and hepatic cholesterol and triglyceride contents have also been studied during the control and glutamate feeding. Cholesterol supplementation (0.05% and 1.0%) did not diminish the hypocholesterolemic response (20–24% decrease in serum cholesterol). The glutamate amino acid formula diet caused no change in serum triglyceride, serum phospholipid, hepatic cholesterol and hepatic triglyceride content when compared to the control formula diet. No lesions of the hypothalamic or paraventricular areas of the brain were noted on histological preparation in adult gerbils given large amounts of glutamic acid orally.