Secondary Transformation Research Articles

Secondary malignant transformation of giant cell tumor of the first metatarsal presenting as a fungating cauliflower like mass- A rare case report

Giant cell tumor (GCT) is the most commonly occurring benign bone tumor. It occurs more commonly in the third decade of life and is slightly more common in females. The knee joint i.e. the distal femur as well as proximal tibia account for most number cases followed by the distal end of radius. The occurrence in foot is rare and usually occurs in the younger age group. The progression in foot is usually accelerated and is masked by vague symptoms and boring type of foot pain. Malignant transformation is rare. In our case the 38 years female patient had GCT of the first metatarsal which later progressed to a secondary malignancy involving the ipsilateral inguinal and femoral lymph nodes. This was later managed by performing a Syme’s amputation along with the involved lymph node dissection. In our single case we noted these salient features of GCT which has a high rate of recurrence, is locally aggressive and has potential for malignant transformation.

Next-Generation Distribution Planning: How Do We Capture the Value of Distributed Energy Resources?

Many studies suggest that distributed energy resources (DERs) have significant value for the distribution system by providing an alternative to conventional system upgrades. Solar photovoltaic (PV) resources can help reduce the flow on lines and substations, and battery storage can help support the capacity to serve load behind a constrained substation transformer. Distributed batteries and smart-inverter-equipped solar can help stabilize the voltage. Taken together, this means investments in conventional solutions for the distribution system, such as upgrades to and the replacement of substations, secondary transformers, and capacitor banks, may be deferred and, in some cases, eliminated.

The seasonal characterization and source analysis of water-soluble inorganic ions in PM2.5 in Fuxin, northeast China

In Fuxin, a few existing studies have illustrated the pollution characteristics of water-soluble ions (WSIIs) in PM2.5 in four seasons. To track the particulate pollution in Fuxin, sample filters of PM2.5 in the four seasons of spring, summer, autumn and winter in 2019 were collected. For the first time, the concentration and seasonal variation characteristics of PM2.5 and WSIIs were tested by gravimeter method and ion chromatography. Characteristics of WSIIs and their existence sources and forms were explored by ion balance calculation, correlation analysis and principal component analysis. The annual average concentrations of PM2.5 and WSIIs were (33.23 ± 13.03) μg·m−3 and (22.86 ± 9.62) μg·m−3, respectively. The seasonal WSIIs concentration followed the order: spring (29.98 μg·m−3) > autumn (28.85 μg·m−3) > winter (21.32 μg·m−3) > summer (11.28 μg·m−3). In WSIIs, 81.41% of them were secondary inorganic ions (SO4 2−, NO3 −, and NH4 +), contributed about 68.80% to PM2.5, and the chemical forms were mainly (NH4)2SO4 and NH4NO3. In this study, it has been revealed that PM2.5 samples exhibited acid properties in spring and autumn while, displayed alkalinity in summer and winter. The average value of NO3 −/SO4 2− was 0.67, so from these data it can be illustrated that fixed pollution sources were found to be dominant over mobile sources in Fuxin. The main identified sources of WSIIs in four seasons in Fuxin were sea salt particles and secondary particles, respectively. These results showed that the geographical factors of Bohai Bay and secondary transformation had a significant impact on the concentration of WSIIs of PM2.5 in Fuxin.

Power-Estimation-Based Synchronous Rectification Solution for Bidirectional DAB-LLC Converter

An LLC-DAB bidirectional converter with reduced switch count as a DC-DC transformer (DCX) is proposed in this paper. It can achieve voltage regulation, full load range zero voltage switching (ZVS) for eight main switches and wide load range ZVS for four auxiliary switches, with consideration of the switch junction capacitors under different power direction. A part portion of total power is transferred through an auxiliary DAB circuit to achieve voltage regulation and bidirectional power conversion. The main power is transferred through LLC circuit with an easy PWM scheme achieving high conversion efficiency. Different from the existing LLC-DAB DCX structure, the two secondary side transformer outputs are in parallel, and connected to the same full-bridge circuit. In this way, the auxiliary DAB circuit can not only adjust the output voltage, but also can inject current into the secondary side to help achieving ZVS of switches without synchronous rectifier (SR) circuit. The converter operation principle is analyzed under different power directions, and ZVS is analyzed with the consideration of all the switch junction capacitors. Based on the analysis, the design consideration is introduced. Finally, a 2-kW prototype with 750V input and 400V output is built up to verify the effectiveness of the proposed solution.

Update on Intensive Care Unit Management of Stroke

In this review, we provide an update on the intensive care unit (ICU) management of ischemic stroke. Over the last decade, new evidence has led to rapid changes in the early management of patients admitted with acute ischemic stroke. Nevertheless, stroke remains a leading cause of disability. Consequently, a significant number of patients with acute ischemic stroke require ICU level care. The most frequent reasons for ICU admissions are large infarction with potential swelling, reduced level of consciousness, secondary hemorrhagic transformation, acute symptomatic seizures or respiratory failure and stroke-related disorders of the brain-heart interaction. Moreover, there is an increasing number of patients receiving intravenous thrombolysis or mechanical thrombectomy with a subsequent need of ICU monitoring. Several studies have shown that the implementation of specialized neuro-intensive care teams help to improve functional outcome after acute ischemic stroke. The main goal in the ICU management of stroke patients is to prevent secondary brain injury. To this end, a comprehensive approach to optimize systemic physiological homeostasis, control intracranial pressure, cerebral perfusion, hemodynamic and respiratory parameters is needed. Here, we summarize recent advances in invasive and non-invasive neuro-monitoring, decision making in decompressive neurosurgery for large supratentorial or cerebellar infarction, specific cardiorespiratory management, nutrition, temperature management and mobilization strategies in ischemic stroke.

Characteristics and source apportionment of PM2.5 under the dual influence of the Spring Festival and the COVID-19 pandemic in Yuncheng city

Based on the online and membrane sampling data of Yuncheng from January 1st to February 12th, 2020, the formation mechanism of haze under the dual influence of Spring Festival and COVID-19 (Corona Virus Disease) was analyzed. Atmospheric capacity, chemical composition, secondary transformation, source apportionment, backward trajectory, pollution space and enterprise distribution were studied. Low wind speed, high humidity and small atmospheric capacity inhibited the diffusion of air pollutants. Four severe pollution processes occurred during the period, and the pollution degree was the highest around the Spring Festival. In light, medium and heavy pollution periods, the proportion of SNA (SO42−, NO3− and NH4+) was 59.6%, 56.0% and 54.9%, respectively, which was the largest components of PM2.5; the [NO3−]/[SO42−] ratio was 2.1, 1.5 and 1.7, respectively, indicating that coal source had a great influence; the changes of NOR (nitrogen oxidation ratio, 0.44, 0.45, 0.61) and SOR (sulphur oxidation ratio, 0.40, 0.49, 0.65) indicated the accumulation of secondary aerosols with increasing pollution. The coal combustion, motor vehicle, secondary inorganic sources and industrial sources contributed 36.8%, 26.59%, 11.84% and 8.02% to PM2.5 masses, respectively. Backward trajectory showed that the influence from the east was greater during the Spring Festival, and the pollutants from the eastern air mass were higher, which would aggravate the pollution. Meteorological and Spring Festival had a great impact on heavy pollution weather. Although some work could not operate due to the impact of the COVID-19 epidemic, the emission of pollutants did not reduce much.

90-yttrium-ibritumomab tiuxetan as first-line treatment for follicular lymphoma: updated efficacy and safety results at an extended median follow-up of 9.6\xa0years

Radioimmunotherapy with 90-yttrium-ibritumomab tiuxetan (90Y-IT) as first-line treatment in patients with follicular lymphoma (FL) demonstrated promising results with a complete remission (CR) rate of 56% and a median progression-free survival (PFS) of 26 months, when initially analyzed after a median follow-up of 30.6 months. The aim of this long-term follow-up was to investigate whether clinical benefits were maintained and new safety signals appeared. Fifty-nine patients, aged ≥ 50 years, with FL grade 1 to 3A in stages II to IV were treated with 90Y-IT as first-line therapy. If CR without evidence of minimal residual disease (MRD), partial response or stable disease was achieved 6 months after treatment, patients were observed without further treatment. Patients with CR but persisting MRD received consolidation therapy with rituximab. The primary endpoint was the clinical response rate. Secondary endpoints were time to progression, safety, and tolerability. After a median follow-up of 9.6 years, median PFS was 3.6 years, and 8-year PFS was 38.3%. Median overall survival (OS) was not reached during the extended follow-up, and 8-year OS amounted to 69.2%. Age 65 years and above or disease progression within 24 months of treatment were significantly associated with shorter OS. An important finding was the lack of new safety signals. In particular, no increase in secondary malignancies or transformation into aggressive lymphoma was observed compared to trials with a similar follow-up. In summary, 90Y-IT as first-line treatment demonstrates a favorable safety profile and long-term clinical activity in a substantial fraction of FL patients in need of therapy. ClinicalTrials.gov Identifier: NCT00772655.

An LLC-DAB Bidirectional DCX Converter With Wide Load Range ZVS and Reduced Switch Count

An LLC dual active bridge (DAB) bidirectional converter with reduced switch count as a dc–dc transformer (DCX) is proposed in this article. It can achieve voltage regulation, full load range zero voltage switching (ZVS) for eight main switches and wide load range ZVS for four auxiliary switches, with consideration of the switch junction capacitors under different power direction. A part portion of total power is transferred through an auxiliary DAB circuit to achieve voltage regulation and bidirectional power conversion. The main power is transferred through LLC circuit with an easy PWM scheme achieving high conversion efficiency. Different from the existing LLC -DAB DCX structure, the two secondary side transformer outputs are in parallel, and connected to the same full-bridge circuit. In this way, the auxiliary DAB circuit can not only adjust the output voltage, but also can inject current into the secondary side to help achieving ZVS of switches without synchronous rectifier circuit. The converter operation principle is analyzed under different power directions, and ZVS is analyzed with the consideration of all the switch junction capacitors. Based on the analysis, the design consideration is introduced. Finally, a 2-kW prototype with 750 V input and 400 V output is built up to verify the effectiveness of the proposed solution.

Hybrid enhancement effect of structural and material properties of the triboelectric generator on its performance in integrated energy harvester

A wind energy harvester (WEH) comprising a coaxial electromagnetic generator (EMG) and a triboelectric nanogenerator (TENG) is proposed to achieve an energy-autonomous closed loop that can harvest widely untapped energy sources for unattended monitoring systems in desolate regions. Energy conversion in the EMG from wind to electrical energy is implemented via the cyclic fixed-axis rotation, whereas that in the TENG is controlled by reciprocating translation driven by the coaxial rotation of the contact-separation structure. However, it is essential, albeit difficult, for TENG to generate a major portion of the wind energy-based electricity by improving the secondary transformation efficiency and reducing wear abrasion. Here, an arrayed contact-separation structure is fabricated with doped and surface-modified friction silicone rubber, large-area arc-shaped substrates, and a Reuleaux triangle plate-cam with local freedom. When the WEH works in one cycle, the TENG runs 12 times. Compared with the single contact-separation structure, the modified friction material significantly increases the output performance of the hybrid enhanced TENG by 104 % and the arrayed cam structure triples the output energy of TENG in a cycle. The maximum output power of the WEH is 54.78 mW at 90 rpm, to which the EMG and TENG contribute approximately 51.57 mW and 3.21 mW, respectively. The share of TENG output energy rivals the results induced by sliding mode TENG in those hybrid energy harvesters of current research. Furthermore, a WEH with an enhanced TENG is experimentally demonstrated by simulating earthquake, fire, and wind speed monitoring. The results indicate the immense potential of the proposed WEH in terms of power supply capability and long-term operation reliability.

Intensified wintertime secondary inorganic aerosol formation during heavy haze pollution episodes (HPEs) in Beijing, China

Air pollution in China is complex, and the formation mechanism of chemical components in particulate matter is still unclear. This study selected three consecutive heavy haze pollution episodes (HPEs) during winter in Beijing for continuous field observation, including an episode with heavy air pollution under red alert. Clean days during the observation period were selected for comparison. The HPE characteristics of Beijing in winter were: under the influence of adverse meteorological conditions such as high relative humidity, temperature inversion and low wind speed; and strengthening of secondary transformation reactions, which further intensified the accumulation of secondary aerosols and other pollutants, promoting the explosive growth of PM2.5. PM2.5/CO values, as indicators of the contribution of secondary transformation in PM2.5, were approximately 2 times higher in the HPEs than the average PM2.5/CO during the clean period. The secondary inorganic aerosols (sulfate nitrate and ammonium salt) were significantly enhanced during the HPEs, and the conversion coefficients were remarkably improved. In addition, it is interesting to observe that the production of sulfate tended to exceed that of nitrate in the late stage of all three HPEs. The existence of aqueous phase reactions led to the explosive growth sulfur oxidation ratio (SOR) and rapid generation of sulfate under high relative humidity (RH>70%).

Mining-Induced Anthropogenic Transformations of the Wielka Kopa Massif—Case Study of Rudawy Janowickie, the Sudetes

The article presents a detailed description of the transformation of the terrain relief due to long-lasting underground and surface mining activity in the Wielka Kopa massif at Rudawy Janowickie (the Western Sudetes mountains). It includes both the anthropogenic forms and secondary transformations of these forms due to natural land-shaping processes, ongoing after mining had been discontinued. The location deserves special attention, as it shows particularly significant mining-induced relief transformations, whose scale can be compared to those of the Walbrzych hard coal basin and the Turoszow lignite basin. The presented object is also an important historical heritage and deserves special attention due to its high research, didactic and tourism potential. The article offers a description of the characteristics and a classification of the anthropogenic forms in the area of Wielka Kopa, which are hoped to serve as an aid in planning future actions related to the revitalization of the area and also as an example for future descriptions of other closed mining facilities.

Measurement report: Particle-size-dependent fluorescence properties of water-soluble organic compounds (WSOCs) and their atmospheric implications for the aging of WSOCs

Abstract. Water-soluble organic compounds (WSOCs) play important roles in atmospheric particle formation, migration, and transformation processes. Size-segregated atmospheric particles were collected in a rural area of Beijing. Three-dimensional fluorescence spectroscopy was used to investigate the optical properties of WSOCs as a means of inferring information about their atmospheric sources. Sophisticated analysis on fluorescence data was performed to characteristically estimate the connections among particles of different sizes. WSOC concentrations and the average fluorescence intensity (AFI) showed a monomodal distribution in winter and a bimodal distribution in summer, with the dominant mode in the 0.26–0.44 µm size range in both seasons. The excitation–emission matrix (EEM) spectra of WSOCs varied with particle size, likely due to changing sources and/or the chemical transformation of organics. Size distributions of the fluorescence regional integration (regions III and V) and humification index (HIX) indicate that the humification degree or aromaticity of WSOCs was the highest in the particle size range of 0.26–0.44 µm. The Stokes shift (SS) and the harmonic mean of the excitation and emission wavelengths (WH) reflected that π-conjugated systems were high in the same particle size range. The parallel factor analysis (PARAFAC) results showed that humic-like substances were abundant in fine particles (< 1 µm) and peaked at 0.26–0.44 µm. All evidence supported the fact that the humification degree of WSOCs increased with particle size in the submicron mode (< 0.44 µm) and then decreased gradually with particle size, which implied that the condensation of organics occurred in submicron particles, resulting in the highest degree of humification in the particle size range of 0.26–0.44 µm rather than in the < 0.26 µm range. Synthetically analyzing three-dimensional fluorescence data could efficiently reveal the secondary transformation processes of WSOCs.

Deep Primary and Secondary Fusion Transformer Based on Internet of Things Technology

As one of the core equipment of power system, power transformer has great fault influence and complex fault causes. In order to ensure the safe and stable operation of power system, its operation state must be monitored and judged. With the increasing maturity of the Internet industry and the continuous development of sensor technology, the emergence of smart grid has contributed to the realization of intelligent transformer on-line monitoring, condition evaluation and fault diagnosis. This paper studies the deep primary and secondary fusion transformer based on the Internet of Things technology, summarizes the development status of intelligent transformer and its existing problems on the basis of relevant literature, and proposes the optimization technology of deep primary and secondary fusion transformer based on the Internet of Things technology to solve its existing problems, and conducts related experiments and fault detection research on the proposed technology. The experimental results show that this optimization technology has good feasibility, good self-state evaluation and fault diagnosis functions. The deep primary and secondary fusion based on the Internet of Things technology proposed in this study can increase the reliability monitoring of intelligent transformer operation, provide a strong technical guarantee for the normal operation of distribution network, and also provide important technical support for the next research of distribution network technology.

A Nano Positioning Platform for STM and Its Compound Control Algorithm

Nano positioning platform, which is widely used in micro and nano measurement field such as scanning tunneling microscope (STM), becomes an indispensable multi-dimensional driving actuator. A good positioning platform is composed of precise mechanical structure, hardware circuits of signal detection, and software control algorithms. However, the nonlinear hysteresis characteristics of piezoelectric actuator (PZT), a common driver, affect the positioning accuracy. Therefore, it is significant to solve the nonlinearity for precise tracking. A nano positioning platform for STM is set up in this article. We propose a compound control algorithm of Bouc–Wen model and fuzzy–proportional–integral–derivative (PID) for STM to compensate and handle PZT’s hysteresis. First, the Bouc–Wen model is established, whose parameters are identified by the genetic algorithm (GA), and the inverse discrete model data can be calculated. Then, the fuzzy theory is applied to the parameters’ self-tuning of the traditional PID algorithm. Finally, the compound control combines open loop and closed loop, which achieves fast response, low overshoot, high precision, and favorable stability. The experimental results show that the proposed algorithm suitable for self-made STM nano positioning platform with small volume, open structure, convenient secondary transformation, easy disassembly, and self-tuning function can greatly improve the hysteresis nonlinearity and realize the accurate positioning.

The direct STAT3 inhibitor 6-ethoxydihydrosanguinarine exhibits anticancer activity in gastric cancer

Signal transducer and activator of transcription 3 (STAT3) plays a key role in promoting tumor malignant progression. Suppression of hyperactivated STAT3 signaling has emerged as a potential therapeutic strategy for many cancer types. In this study, the effect of 6-ethoxydihydrosanguinarine (6-EDS), a secondary transformation product formed from dihydrosanguinarine, isolated from Macleaya (Papaveraceae), was evaluated in gastric cancer (GC). We demonstrated that 6-EDS inhibited the survival, migration, and invasiveness of GC cells in vitro. Moreover, 6-EDS inhibited STAT3 phosphorylation and transcriptional activity, thus suppressing the mRNA expression of downstream target genes associated with the malignant survival, migration, and invasiveness of GC cells. Molecular docking indicated that 6-EDS directly bound the SH2 domain of STAT3. Molecular dynamics simulations suggested that 6-EDS inhibited the binding of phosphorylated and non-phosphorylated STAT3 to target DNA. Cellular thermal-shift assays and microscale thermophoresis further confirmed the direct binding of 6-EDS to STAT3. Site-directed mutagenesis indicated that the S611 residue in the SH2 domain of STAT3 is critical for 6-EDS binding. In vivo, 6-EDS decreased tumor growth in xenografted nude mice by blocking STAT3 signaling. These findings indicated that 6-EDS, a direct STAT3 inhibitor, may be a potent anticancer candidate for GC therapy.

Soil Chemistry and Clay Mineralogy of an Alluvial Chronosequence from the North Carolina Sandhills of the Upper Coastal Plain, USA

Temporal changes in soil development were assessed on fluvial terraces of the Little River in the upper Coastal Plain of North Carolina. We examined five profiles from each of six surfaces spanning about 100,000 years. Soil-age relationships were evaluated with inter-surface clay mineral comparisons and regression of chemical properties versus previously reported optically-stimulated luminescence ages using the most developed subsoil horizon per profile. Bases to alumina (Bases/Al2O3) ratios have negative correlations with age, whereas dithionite-Fe (FeD) concentrations are positively correlated with time and differentiate floodplain (<200 yr BP) from terrace (≥10 ± 2 ka) soils and T4 pedons (75 ± 10 ka) from younger (T1-T3b, 10 ± 2–55 ± 15 ka) and older (T5b, 94 ± 16 ka) profiles. Entisols develop into Ultisols with exponentially decreasing Bases/Al2O3 ratios, reflecting rapid weatherable mineral depletion and alumina enrichment during argillic horizon development in the first 13–21 kyr of pedogenesis. Increasing FeD represents transformation and illuviation of free Fe inherited from parent sediments. Within ~80–110 kyr, a mixed clay mineral assemblage becomes dominated by kaolinite and gibbsite. Argillic horizons form by illuviation, secondary mineral transformations, and potentially, a bioturbation-translocation mechanism, in which clays distributed within generally sandy deposits are transported to surface horizons by ants and termites and later illuviated to subsoils. T5b profiles have FeD concentrations similar to, and gibbsite abundances greater than, those of pedons on 0.6–1.6 Ma terraces along Coastal Plain rivers that also drain the Appalachian Piedmont. This is likely because the greater permeability and lower weatherable mineral contents of sandy, Coastal Plain-sourced Little River alluvium favor more rapid weathering, gibbsite formation, and Fe translocation than the finer-grained, mineralogically mixed sediments of Piedmont-draining rivers. Therefore, recognizing provenance-related textural and mineralogical distinctions is crucial for evaluating regional chronosequences.

Comparative study of the inhibitory effects of lotus seedpod oligomeric procyanidins on dietary AGE released from glycated casein during digestion

Glycation of protein results in the formation of advanced glycation end-products (AGEs), which are further absorbed by the body through digestion in the gastrointestinal tract. The inhibitory properties of procyanidin for the release of AGEs from glycated proteins are of great significance in promoting, accelerating or stabilizing gastrointestinal folding intermediates, although the mechanism of action remains unclear. With the background of dairy processing, the study investigated the inhibitory effect of lotus seedpod oligomeric procyanidins (LSOPC) and its three monomers on AGE release from glycated casein (G-CS) during gastrointestinal digestion. In gastrointestinal microenvironments, multispectral and microscopy analysis were used to investigate interaction mechanisms. Results showed that the binding force of the protein-procyanidin complexes were hydrogen bonding and hydrophobic interaction and LSOPC leaded the G-CS secondary structure transformations furtherly. In the gastric environment, all monomers displayed stronger binding to pepsin but in the intestinal environment, results were opposite. Molecular docking showed that procyanidins were bound in the internal cavity of G-CS, pepsin and pancreatin, thereby forming a relatively stable binding conformation. Moreover, procyanidins enhanced the antioxidant capacity of G-CS, which could attenuate postprandial oxidative stress in the gastrointestinal tract caused by the release of AGEs. Together, this study improves our understanding of dietary AGEs during gastrointestinal digestion.

Customized Flagelliform Spidroins Form Spider Silk-like Fibers at pH 8.0 with Outstanding Tensile Strength

Spider flagelliform silk shows the best extensibility among various types of silk, but its biomimetic preparation has not been much studied. Herein, five customized flagelliform spidroins (FlSps: S and NTDFl-Sn-CTDFl, n = 1–4), in which the repetitive region (S) and N-/C- terminal domains (NTDFl and CTDFl) are from the same spidroin and spider species, were produced recombinantly. The recombinant spidroins with terminal domains were able to form silk-like fibers with diameters of ∼5 μm by manual pulling at pH 8.0, where the secondary structure transformation occurred. The silk-like fibers from NTDFl-S4-CTDFl showed the highest tensile strength (∼250 MPa), while those ones with 1–3 S broke at a similar stress (∼180 MPa), suggesting that increasing the amounts of the repetitive region can improve the tensile strength, but a certain threshold might need to be reached. This study shows successful preparation of flagelliform silk-like fibers with good mechanical properties, providing general insights into efficient biomimetic preparations of spider silks.

Development of a Methodological Approach to Identifying Petrophysical Types of Complicated Carbonate Rocks According to Laboratory Core Studies

Petrophysical typification of productive hydrocarbon deposits is one of the main stages of building a petrophysical model of a reservoir. For carbonate reservoirs characterized by a heterogeneous complex structure of the void space, the problem of identifying petrotypes is very relevant. An extensive literature review of existing methods of petrophysical typification showed that the most well-known and widely used of them were based on simple theoretical models of the structure of the void space of rocks, which did not allow a full description of complex carbonate deposits. Moreover, the petrotypes identified on the basis of these methods did not agree with the results of microdescription of thin sections. A new methodological approach to the identification of petrophysical types of complex carbonate rocks was proposed, based on the integration of the results of standard (determination of the absolute gas permeability and open porosity coefficients) and special (nuclear magnetic resonance studies) core studies and data obtained in the lithological description of thin sections. The developed approach took into account the main petrophysical properties of rocks that characterize its reservoir potential, as well as the structural features of the void space and the influence of secondary transformations. The proposed methodological approach was applied to distinguish petrophysical types in the section of the Assel-Sakmara deposits of the Yareyuskoye field: six petrotypes were identified and described in detail, combined into four zones (zone of development of healed fracturing, zone of development of leaching, zone of development of leaching and open fracturing, zone of development open fracturing), for each of them, individual dependences of the absolute gas permeability coefficient on the open porosity coefficient and the Leverett J-function on the water saturation coefficient were constructed. The information obtained would allow a differentiated approach to geological and hydrodynamic modeling of a hydrocarbon reservoir.

Development of a mechanically stable human hair keratin film for cell culture

An easy-to-handle keratin film was successfully fabricated using solely purified hair keratins. Keratin was extracted from human hair by an existing protocol. The extracted keratin was made into a mechanically stable film by solution casting and air-drying at room temperature. The films obtained were characterized for surface morphology, wettability, protein secondary structures, mechanical properties, permeability, and thermal properties. Interestingly, the keratin film showed distinct surface and cross-sectional morphology, and protein secondary structure transformation. In addition, the keratin film exhibited Young’s modulus of 1.05 ± 0.09 GPa when it was dry. In the wet state, the keratin film behaved as viscoelastic material and was highly stretchable at 179 ± 17% strain at break. Permeability test was conducted using 20 kDa-FITC dextran which revealed an anomalous diffusion mechanism through the keratin film. Additionally, the keratin film elicited positive cellular responses by human epidermal keratinocytes (HEKs) in terms of enhanced cell proliferation, viability, keratin 14 expression, and IL-1α secretion, in comparison to collagen I. Taken together, a human hair keratin-based film with its mechanical and thermal stability, and cytocompatibility, presents a promising platform for cell culture applications.