Dry Procedure Research Articles

Safety Events and Privilege Utilization Rates in Advanced Practice Physical Therapy Compared to Traditional Primary Care: An Observational Study

The general practitioner shortage in the United States coupled with a growing number of Americans living with disability has fueled speculation of non-physician providers assuming a greater role in musculoskeletal healthcare. Previous physician shortages have been similarly addressed, and expanding physical therapy (PT) scope of practice may best serve to fill this need. Resistance to expanding PT practice focuses on patient safety as PTs assume the roles traditionally performed by primary care providers. While studies have shown advanced practice PT to be safe, none have compared safety events in advanced practice PT compared to primary care to determine if there are increased patient risks. Therefore, the purpose of our study is to examine the rate of safety events and utilization of services in an advanced practice PT clinic compared to a primary care clinic. A secondary aim of our study was to report safety events associated with spinal manipulation and dry needling procedures. Productivity and safety data were retrospectively collected from Malcolm Grow Medical Center from 2015 to 2017 for the Family Health Clinic (FHC) and an advanced practice Physical Therapy Clinic (PTC). Chi-square tests for independence, risk ratios (RR) and 95% confidence intervals (95%) were used to compare the relationship between the frequency of (1) patient encounters and clinical procedures and (2) clinical procedures and safety events. Seventy-five percent (12/16) of safety events reported in the PTC were defined as near misses compared to 50% (28/56) within the FHC (RR 1.5; 95% CIs: 1.0 to 2.2). Safety events were more likely to reach patients in the FHC compared to the PTC (RR 1.9; 95% CIs: 0.8 to 4.7). Safety events associated with minor harm to patients was n = 4 and n = 3 in the FHC and PTC respectively. No sentinel events, intentional harm events, nor actual events with more than minor harm were reported in either clinic. Significant relationships indicated that prescriptions, laboratory studies, imaging studies and referrals, were all more likely to be ordered in the FHC than the PTC (p < 0.01). The PTC ordered one diagnostic imaging study for every 37 encounters compared to one in every 5 encounters in the FHC. The PTC similarly referred one patient to another healthcare provider for every 52 encounters, fewer than the one per every 3 encounters in the FHC. There was a significant relationship between encounters and diagnoses, indicating a higher number of diagnoses per encounter in the FHC, though the difference of 0.31 diagnoses per encounter may not be clinically meaningful (p < 0.01). A total of 1,818 thrust manipulations and 2,910 dry needling procedures were completed without any reported safety events. These results suggest advanced practice PT has a similar safety profile to primary care. The authority to order musculoskeletal imaging and refer to other clinicians were among the most commonly utilized privileges and may be of primary importance when establishing an advanced practice PT clinic. These results support research showing advanced practice PT may lead to reductions in specialty referrals, diagnostic imaging, and pharmaceutical interventions.

Solid-to-liquid transition of polycarbonate solid electrolytes in Li-metal batteries

In this work, we analyzed the thermal stability of polycarbonate: lithium trifluoromethane sulphonylimide (LiTFSI) systems. Polyethylene carbonate (PEC) and polypropylene carbonate (PPC) undergo depolymerization to ethylene carbonate (EC) and propylene carbonate (PC), respectively, in the presence of Li salt under annealing treatment. The decomposition reaction can explain the surprising high ionic conductivity recently reported for solid polymer electrolyte (SPE) polycarbonate-based systems. Because this phenomenon can strongly impact the results of SPE research, it is essential to control the depolymerization of polymers to avoid inaccurate electrochemical performance. In addition, we observed that the standard drying procedure for the preparation of high-salt-concentration polymer (polymer-in-salt) SPEs traps a high amount of residual solvent, e.g., acetonitrile (ACN), due to the strong bond between the solvent and ionic species. This finding represents another factor influencing the remarkably high ionic conductivity.

Behaviour of saturated fibre-reinforced sand in centrifuge model tests

Fibre-reinforcement has shown its efficacy in improving soil properties and been proposed to apply in increasing liquefaction resistance of deposits. As the contributions of fibres in real seismic conditions are yet to clarify, further investigations are needed to fill this gap. In this study, centrifuge tests have been conducted for this exploration. The dry pluviation preparation procedures for fibre-reinforced sand in centrifuge testing are disclosed in details for the first time. Results show that fibres are beneficial in preventing structure collapse of the sand matrix, but liquefaction induced excess pore pressures and ground surface settlements reduction is not apparently reduced as those in previous tests. Shear moduli are enhanced to some extent under lower confining stresses at relative larger shear strain levels, while equivalent damping ratios are increased at small strain levels. Limitation of simulating real conditions of previous element tests and 1 g shaking table tests may exaggerate the benefits of fibres.

Copper, manganese, iron and zinc contents of Nigerian foods and estimates of adult dietary intakes

The levels of some microminerals – copper, manganese, iron and zinc – were determined in 605 individual food samples representing 141 different foods across 11 food groups. The samples were collected ‘as consumed’ from ten towns and cities located in Ogun State and Federal Capital Territory, Abuja, Nigeria. They were analysed using flame atomic absorption spectrometry after dry ashing procedure. The levels (mg/100g fresh weight) of these minerals ranged from non-detectable (nd) to 3.00, nd to 3.85, 0.042 to 16.5 and 0.014 to 13.2 for copper, manganese, iron and zinc, respectively in the diverse foods. At the food group level, the mean mineral levels were significantly different (P < 0.05) from one another. The mineral concentration data obtained from most of these foodstuffs are similar to those available in reports from other countries around the world. Using the mainly data obtained from the foods analysed, estimate of the adult mean daily mineral intakes (mg/person/day) were 2.7 ± 1.0, 3.7 ± 1.7, 22.3 ± 7.8 and 8.7 ± 3.4 for copper, manganese, iron and zinc, respectively. These mean intakes are within international recommendations and thus indicate safety of consumers. The data obtained from this study is useful in updating the Nigerian food composition database.

Maize meal slurry mixing: an economical recipe for precise aflatoxin quantitation

The laboratory sample preparation for mycotoxin determination in cereals, often overlooked among sampling plans and analytical methods, was further studied. The precision of aflatoxin analysis in comminuted maize samples using 25 g slurry (prepared from 250 g test portion of comminuted maize, water/matrix (1+1, v/w)) and 12.5 g dry grind test portion were compared against the conventional 50 g dry grind test portion through replicated (10) Aflatest® immunoaffinity fluorometric tests of naturally contaminated samples with aflatoxin concentration ranging from 4.9 to 81.7 μg/kg. The overall mean aflatoxin concentration obtained from the 10 different samples tested using 12.5 g and 50.0 g dry grind procedures was 12% significantly (P&lt;0.05) lower (poorer) compared to 25 g slurry. The sample preparation plus analytical variance associated with testing 25.0 g slurry, 50.0 g dry grind and 12.5 g dry grind test portions were in the ratio of 1:5:15, respectively.

Towards efficient oxygen reduction reaction electrocatalysts through graphene doping

The incessant and drastic growth of global energy demand make it imperative to develop new affordable high-quality materials at a large scale to act as powerful electrocatalysts (ECs) on the relevant energy reactions.Here, we report the synthesis and characterization (FTIR, Raman, XPS, XRD, TEM and SEM) of new engineered electrocatalysts based on situ co-precipitation of Co3O4 or Mn3O4 nanoparticles in the presence of N, S-doped graphene (Co/N3S3-GF and Mn/N3S3-GF). The nitrogen, sulphur dual-doped graphene was achieved by a scalable dry ball-milling procedure followed by thermal treatment using graphene flakes as carbon source and trithiocyanuric acid as the precursor.The three materials prepared were applied as electrocatalysts for the oxygen reduction reaction (ORR) and demonstrated excellent electrocatalytic performance in alkaline medium with Co/N3S3-GF and Mn/N3S3-GF presenting onset potentials of 0.87 V vs. RHE. These were comparable to Pt/C onset potential (0.91 V). All materials showed good diffusion-limiting current densities (−3.49 to −4.17 mA cm−2) and selectivity for the 4-electron O2 reduction to H2O. Furthermore, the Co/N3S3-GF and Mn/N3S3-GF electrocatalysts presented good tolerance to methanol poisoning and good stability with current retentions (76–81%).The approach followed in this work showed that affordable, simple and scalable procedures can be applied to develop ORR electrocatalysts with enhanced performances.

Key Features in the Manufacturing Process of Ultra-Thick Electrodes for High Energy Lithium Ion Batteries

Energy density is one of the key challenges in the development of advanced lithium ion batteries for many applications. To address this issue, a considerable number of studies have been conducted on high capacity cathode materials1–3. Another approach, covered in this contribution, is reducing the amount of passive material in the cell via increasing the mass loading of the electrodes4,5. These ultra-thick electrodes, however, suffer from certain drawbacks like a low rate capability4–7, reduced adhesion and flexibility or crack formation8. Numerous investigations on the development of electrodes for lithium ion batteries have been performed using preparation techniques typical for lab scale. In common studies, the electrochemical and mechanical properties of an electrode are attributed to mass loading, porosity and the distribution of passive materials in the binder-network9. This study considers manufacturing procedures for NMC cathodes highly relevant to industrial production. A strong influence of the manufacturing process especially on the morphology and electrochemical performance of ultra-thick electrodes was observed. As an example, ultra-thick electrodes with an areal capacity of 8 mAhcm-2 were prepared in pilot scale, yielding a significantly higher capacity than state of the art cathodes7,10. It is demonstrated that the mixing strategy used for slurry preparation significantly alters the distribution of materials and the morphology of the electrode, consequently also influencing adhesion strength and flexibility. These properties are likewise strongly affected by the applied drying procedure. By an optimized mixing and drying procedure, crack-free, ultra-thick electrodes were obtained even in pilot scale. These electrodes, manufactured by the optimized process, show significantly higher flexibility, which is very important for roll-to-roll processing. Scanning electron microscopy revealed the strong effect of the manufacturing process on the morphology of the material distribution within the electrode composite. Electrochemical measurements and impedance spectroscopy furthermore showed the decisive influence of electrode morphology on rate capability and Li+ transport properties. As a result, only by applying an improved mixing process, the areal discharge capacity of ultra-thick cathodes at 1 C was increased by more than 50% compared to a common procedure. Figure 1

Characterization of physicochemical properties and antioxidant activity of polysaccharides from shoot residues of bamboo (Chimonobambusa quadrangularis): Effect of drying procedures

In the present study, the bamboo shoot (Chimonobambusa quadrangularis) residue (BSR)-derived polysaccharides (CPS) were dried using different drying procedures, including hot air-, vacuum-, freeze-, and spray-drying. The influences of different drying procedures on the chemical compositions, physicochemical characteristics, and antioxidant activity of CPS were investigated. The results indicate that freeze-dried CPS possessed the highest polysaccharide yield (8.86%) and uronic acid content (9.42%), and the lowest medium-high molecular weight (117.49 kDa) and glucose content (5.81 mol%). Also, freeze-dried CPS had better water (5.17 g/g) and oil retention capacities (2.32 g/g) than hot air- and vacuum-dried CPS. Moreover, freeze-dried CPS exhibited the most potent antioxidant ability. Based on correlation analysis, a higher uronic acid content, lower molecular weight and lower glucose content might be closely associated with the better antioxidant activity of the freeze-dried CPS. Hence, the above results revealed freeze-drying was the optimal method for industrial production of high quality CPS.

Short communication: Effects of drying and analytical methods on nitrogen concentrations of feeds, feces, milk, and urine of dairy cows

Nitrogen concentrations in feeds, feces, milk, and urine samples were measured using 2 analytical methods following different drying procedures. Ten samples of corn silage, alfalfa silage, and concentrates collected from 2017 to 2018 at Krauss Dairy Research Center, The Ohio State University (Wooster), were used. A 4-d total collection digestion trial provided fecal samples from 10 cows (1 sample/cow), and another 10 cows were used to collect milk samples (1 sample/cow) and spot urine samples (1 sample/cow). Spot urine samples were acidified immediately to pH <3.0 when collected. Feed samples were oven dried (55°C) or lyophilized and analyzed using the Kjeldahl (KJ; copper sulfate as a catalyst) method and a combustion method (elemental analyzer; EA). Feces, urine, and milk samples were analyzed for N using the following methods: (1) fresh samples by KJ (referred to as wet KJ), (2) lyophilization (urine and milk for 8 h; feces for 120 h) followed by EA (LYO-EA), and (3) oven drying (milk and urine for 1 h; feces for 72 h at 55°C) followed by EA (OD-EA). Additionally, changes in N content of acidified urine at -20° over 180 d of storage were examined. Nitrogen concentrations in corn silage, alfalfa silage, and concentrates were greater for EA by 6.1, 4.8, and 8.3%, respectively, compared with KJ. Analysis of dried samples via EA compared with wet KJ resulted in lower fecal N content (27.8 vs. 29.3 g/kg of DM). Nitrogen concentration in fecal samples via KJ after lyophilization was lower by 5% compared with wet KJ but did not differ from LYO-EA, suggesting that N losses occurred during drying. Nitrogen determination with EA after drying of samples resulted in greater milk N (5.70 vs. 5.50 g/kg) and urinary N (9.16 vs. 9.06 g/kg) content compared with wet KJ. However, drying method (i.e., lyophilization vs. oven drying) did not affect N content of milk, urine, or feces. The use of EA resulted in lower percentage deviation of N content from duplicate sample assays for most samples (no difference was found for concentrate and fecal N), suggesting that EA was more precise than KJ. In conclusion, drying of feces caused N losses regardless of drying methods. For urine and milk samples, if drying is necessary (i.e., EA), oven drying at 55°C can be used rather than lyophilization. The N content was greater in feeds, milk, and urine when determined with EA versus KJ. In addition, N content in acidified and undiluted urine at -20° changed and should be analyzed within 90 d of storage. The results in the current study, however, did not account for laboratory-to-laboratory variation.

Relationship between band-offset, gate leakage current, and interface states density at SiO2/4H-SiC (000-1) interface

We investigated the relationship between the band-offset, the gate leakage current, and the interface states density on SiO2/4H-SiC (000-1) structures via hard x-ray photoelectron spectroscopy and electrical measurements. From the observed band-offset, we found that conduction band offset (ΔEc) depended on the oxidation procedure, but valence band-offset (ΔEv) did not. In addition, ΔEv was larger than ΔEc, indicating that electron tunneling was more predominant than hole tunneling. SiO2 prepared by a dry oxidation procedure exhibited the highest gate leakage current onset and the highest interface states density and the largest ΔEc, whereas a wet oxidation procedure produced the lowest gate leakage current onset, the lowest interface states density, and the smallest ΔEc. Oxygen annealing after wet oxidation effectively increased gate leakage current onset, which increased the interface states density and the ΔEc. These results were related to hydrogen atoms and carbon related defects at the SiO2/4H-SiC (000-1) interface.

Utility of dry load injection for an efficient natural products isolation at the semi-preparative chromatographic scale

Semi-preparative HPLC is one of the main techniques used for the purification of natural products (NPs). Generally, the sample has to be solubilized in organic solvent and injected on column through a loop valve. Since the solubility of crude natural extracts is often limited, a high solvent volume is needed for injection. This significantly compromises the resolution and increases the risk of overpressure in the system. To overcome this problem, a dry load injection procedure was developed to ensure optimum resolution even at high sample loading. The approach was first validated with a representative mixture of NPs standards, and successfully applied to two representative crude plant extracts: the dichloromethane extract of Annacardium occidentale and the methanolic extract of Hypericum perforatum. In all cases, the dry loading injection setup enabled an efficient introduction of the samples in the semi-preparative HPLC system. Different overload conditions of the columns were tested and the results demonstrated the robustness of the method and the possibility of applying it with a limited loss of resolution compared to liquid injection and without increasing pressure. The chromatographic resolutions were close to those obtained at the analytical level and separation were of much better quality when compared to liquid injection. This approach is especially relevant when purifying compounds isolated with high resolution from extracts that are poorly soluble in low volume of injection solvent due to the presence of lipophilic compounds and are thus not compatible for loop injection in typical reversed phase conditions. In addition, the dry load setup was also found to be useful when relatively polar components have to be separated in reversed phase conditions. In this case, loop injection with methanol generates strong peak distortion and broadening, while the dry load injection affords symmetrical peaks.

Effect of Gender and Procedure on Patient-Reported Dry Eye Symptoms After Laser Vision Correction.

To evaluate factors associated with the change in dry eye symptoms following laser vision correction. This was a retrospective case series of 13,319 patients who underwent laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) between January 2013 and February 2016 and completed a preoperative and 3-month postoperative patient-reported outcome questionnaire. In a multivariate linear regression model, women and contact lens wearers were associated with worse preoperative dry eye symptoms. Age was not significantly associated with preoperative dry eye symptoms. The change in dry eye symptoms preoperatively to postoperatively was affected by gender, procedure type, and preoperative dry eye symptoms. Patients who underwent PRK were more likely to report an increase in dry eye after 3 months (coefficient: 3.99, 95% confidence interval (CI): 1.64 to 4.82, P < .001) and patients with worse preoperative dry eye were more likely to have improvement in symptoms after surgery (coefficient: -0.93, 95% CI: -0.97 to -0.90, P < .001). More women reported an increased level of symptoms 3 months after surgery than men (coefficient: 1.76, 95% CI: 0.68 to 2.84, P = .001). Preoperative dry eye symptoms, female gender, and procedure type had a significant effect on preoperative to postoperative change in dry eye symptoms after laser vision correction. Age was not associated with dry eye symptoms in this population. [J Refract Surg. 2019;35(3):161-168.].

FROM HARVESTING TO DISTILLATION – EFFECT OF ANALYTICAL PROCEDURES ON THE YIELD AND CHEMICAL COMPOSITION OF RHODODENDRON TOMENTOSUM (LEDUM PALUSTRE) ESSENTIAL OIL

Rhododendron tomentosum possesses the anti-inflammatory, analgesic and antimicrobial properties, determined by the chemical composition of its essential oil. The effects of place (Miszewko, Lubichowo) and time of harvesting (June, November) as well as drying (air-drying, oven-drying, freeze-drying) and isolation (in Deryng, Clevenger and Likens-Nickerson apparatus) procedures on the yield and quality of R. tomentosum essential oil were studied. Ledol (8.1-14.4%), palustrol (6.9-13.0%) and γ-terpineol (8.5-9.1%) predominated in the plants collected from Miszewko, while γ-terpineol (11.8-22.2%), p-cymene (5.3-12.6%) and geranyl acetate (5.7-7.5%) prevailed in the biomass from Lubichowo. The shoots produced more volatiles in the flowering phase than at the end of the vegetation. Oven-drying at 30OC with controlled air flow was suggested as the quick dehydration method. Hydrodistillation in Deryng and Clevenger apparatus resulted in comparatively high essential oil yield (about 1%). All studied drying and distillation methods did not influence significantly the general profile of R. tomentosum essential oil

Assessment of the use potential of iron ore tailings in the manufacture of ceramic tiles: From tailings-dams to “brown porcelain”

Abstract Nearly half of the total iron ore volume extracted in mining operations is rejected as tailings and disposed of in containment dams that are liable for considerable environmental impact and human hazard in case of breaching. This work aims to expand the usage possibilities of iron ore tailings and help mitigate the negative impact of tailings-dams without sacrificing the opportunities provided by mining. Materials were collected from four tailings-dams, subjected to a dry separation procedure and characterized (particle size and morphology, chemical and mineralogical composition). Besides the recovered iron ore concentrate, two other powder fractions were produced (“clay” and “sand” fractions). The sands showed the greatest uniformity (particle size and shape, mineralogy and chemical composition) and may find use as aggregates in a variety of applications. This work shows that the clays can be used on their own in the production of ceramic tiles. They present adequate plasticity and dry strength, and develop mullite and glass upon firing, showing a rather amenable processing behaviour suitable for both artisanal and full-fledged industrial production. The resulting tiles are dimensionally homogeneous and very compact (vitrified products, classified in groups BIa, BIb or BIIa), with high mechanical strength. Either industrialised or artisanal, these materials can be used in the production of “brown porcelain” tiles and ware, showing a very appealing dark brown lustre.

Origin of the dry etch damage in the short-channel oxide thin-film transistors for high resolution display application

The demand for high-resolution displays with fine pitch has been continuously increased. Source/drain (S/D) dry etching is indispensable when defining very narrow patterns, but back-channel damage is inevitable when it is carried out, which can lead to deterioration in the performance of devices made with them. Nevertheless, thorough analysis on the etch damage was not yet conducted in depth. In this study, the phenomenon and the reason of etch damage occurring in S/D dry etch procedure of back-channel-etched oxide thin-film transistors were evaluated. Right after S/D dry etching process, small amount of molybdenum (S/D metal) and chlorine (main etching gas) were detected on the back-channel surface. The changes in the chemical bonding state of the back-channel surface and the resulting degradation of device performance were examined in detail. Furthermore, a highly efficient wet treatment method was introduced to restore the etch damage. By doing so, all of the device characteristics were notably enhanced compared to a device not subjected to the wet treatment process.

A randomized trial of trigger point dry needling versus sham needling for chronic tension-type headache.

Background:In this randomized, double-blind, parallel-group trial, we aimed to explore the effectiveness of trigger point dry needling in patients with chronic tension-type headache in reducing headache frequency, intensity and duration, and improvement of health-related quality of life.Methods:The 168 patients in 2 neurology clinics with chronic tension-type headache. The participants were randomly assigned to one of two treatment groups for dry needling or sham dry needling, delivered in 3 sessions a week for 2 weeks. The 160 patients fulfilled the study requirements. The dry needling was applied in active trigger points located in the musculature of the head and the neck. The patients received dry needling using sterile stainless-steel acupuncture needles of 0.25 × 40 mm and 0.25 × 25 mm dimensions. The sham dry needling procedure was applied into the adipose tissue located at any area where an active trigger point was absent. The primary outcome measurement was the headache intensity. Secondary outcomes were frequency and duration of headache, and quality of life, assessed by the Short Form-36. All outcomes were measured at baseline, at the end of 2-week, and 1-month follow-up period.Results:In the dry needling group, intensity, frequency and duration of headache, and the scores of Short Form-36 subscales were significantly improved after treatment (P < .05). In the dry needling group, all the effect sizes for headache variables were large.Conclusions:The results of this clinical trial suggest that trigger point dry needling in patients with chronic tension-type headache is effective and safe in reducing headache intensity, frequency and duration, and increasing health-related quality of life.Trial registration:Clinical Trials NCT03500861.

Evaluation of microbial quality of street food in Karachi City, Pakistan: An epidemiological study

The purpose of this research was to evaluate the microbial quality of famous street foods vended in Karachi city and find out the potential sources implicated in food contamination. To proceed with this study, dry and wet procedures were used via closed system questionnaire and gold standard techniques respectively. According to the questionnaire survey, majority of people have basic knowledge of food borne sickness i.e. 67% and health risks associated with poor eating habits i.e. 87%, nonetheless most individuals do not mind their cleanliness before eating on spot. A large number of people had come across different food borne infections subsequent to eating street foods. Total mean aerobic count was 7.18±1.26 CFU/ml that was not under the acceptable microbial limits. The highest total viable count 9.15±0.01 CFU/ml and the lowest total viable count 4.67±4.04 CFU/ml recorded were of grilled chicken and fried fish respectively. Poor post handling and personal cleanliness of food venders were ascribed to high bacterial count in completely cooked street foods.

Dry Process for Fabricating Low Cost and High Performance Electrode for Energy Storage Devices

AbstractWe report a roll-to-roll dry processing for making low cost and high performance electrodes for lithium-ion batteries (LIBs). Currently, the electrodes for LIBs are made with a slurry casting procedure (wet method). The dry electrode fabrication is a three-step process including: step 1 of uniformly mixing electrode materials powders comprising an active material, a carbonaceous conductor and the soft polymer binder; step 2 of forming a free-standing, continuous electrode film by pressing the mixed powders together through the gap between two rolls of a roll-mill; and step 3 of roll-to-roll laminating the electrode film onto a substrate such as a current collector. Compared with the conventional wet slurry electrode manufacturing method, the dry manufactural procedure and infrastructure are simpler, the production cost is lower, and the process eliminates volatile organic compound emission and is more environmentally friendly, and the ability of making thick (&gt;120µm) electrodes with high tap density results in high energy density of final energy storage device. A prototype LIBs of LiNi0.6Mn0.2Co0.2O2 (NMC622)/graphite also has 230 Wh/ kg energy density.

Study of dry‐ and wet‐process amorphous arsenic sulfides: Synthesis, Raman reference spectra, and identification in historical art materials

AbstractThis paper reports the dry and wet synthetic procedures and characterization by Raman spectroscopy of amorphous arsenic sulfide reference pigments. Reference spectra of two amorphous materials obtained by wet process methods and four dry process references of amorphous arsenic sulfide pigments of known composition are presented and discussed.While all materials present a main band characteristic for the amorphous pigment centered on 341 cm−1, additional small contributions indicate the presence of sulfur, arsenic oxide, and crystalline nano phases embedded in the amorphous matrix. Although only the broad 341‐cm−1 peak is necessary to identify the arsenic sulfide as an amorphous material, the smaller additional features allow for the characterization of the various manufacturing processes and initial materials used. In ideal conditions, these small features also enable to assess the As/S ratio of the studied amorphous arsenic sulfide pigments based on their relative intensity. In this context, the latter reference spectra were used to characterize the amorphous arsenic sulfide pigments and their arsenic to sulfur elemental composition in four 18th‐ to 20th‐century historical samples and compared with scanning electron microscopy with energy dispersive X‐ray semiquantitative analyses. The identification of the amorphous arsenic sulfide used in these historical samples was compared with the description of the manufacturing processes reported in historical sources of the time, allowing for a better understanding of the evolution of the amorphous arsenic sulfide pigments manufacturing methods.

A STUDY OF AREA AND THICKNESS COMPRESSION OF PARAFFIN SECTIONS

This study was carefully designed to determine the section compression of paraffin embedded sections. Two sections (one with thickness 5 µm and one 10 µm set by microtome) were cut from each of 2 sets of 12 testicular tissue (adult rats) blocks and stained with hematoxylin. Using scanned images, the area and the vertical (along the sectioning direction) and horizontal diameters of the block face were measured and compared with those of the unstained, stained or coverslipped section. Using the coverslipped section, the vertical and horizontal diameters of round spermatid nuclear profiles and the actual thickness of section were measured with light microscopy. Overall, the area of the coverslipped section was reduced by 5.5%-8.6% (on average) in comparison with that of the block face, with 69.5%-84.4% of the reduction being contributed by section compression in the process of section cutting, mounting and drying. The vertical (linear) compression of section, the primary cause of section area compression, was 5.9%-8.9%. The vertical compression of nuclear profiles was 1.5%-2.3% in 2 sets of sections and 5.2%-5.7% in other sections, indicating a non-uniform compression of structures within some sections depending on procedures of section drying. The measured mean thickness of sections decreased by 3.1%-5.0%.