Crystal Powder Research Articles

The Significance of Local Intraoperative Hemostasis and Laser Influence in the Prevention and Treatment of Complications During Thyroid Surgery

The article presents the results of clinical studies on the development of a method for local intraoperative hemostasis and improvement of reparative processes during operations on the thyroid gland. For clinical evaluation of the effectiveness of the proposed method, two study groups were formed for 237 patients with mixed, nodular and diffuse toxic goiter. The main group consisted of 98 patients, and the comparison group - 139. In the main group of operated patients, hemostasis was carried out according to the method developed by us, and in the comparison group, by traditional methods. Surgery included thyroidectomy, hemithyroidectomy, and subtotal thyroidectomy. In the main group of patients, for the purpose of hemostasis, Hemoben powder crystals with a size of 25-50 microns were used at the rate of 200 mg per area of 8-9 cm2, which was applied over the wound with a thin layer until a thin translucent film was formed, followed by irradiation of the wound with low-energy laser radiation (Sogdiana apparatus) with a wavelength of 0.89 microns, a frequency of 500 Hz for 2 minutes at a distance of 5 cm from the wound; then, for 5-7 days, percutaneous irradiation sessions with the same laser at a frequency of 80 Hz were performed daily in the projection of the surgical wound. The study showed that the use of the domestic hemostatic agent Hemoben provides complete hemostasis, and the addition of the technique by treating the surgical field with low-intensity laser radiation enhances the reparative properties of the drug. The proposed method for local hemostasis and improvement of reparative processes during thyroid surgery is characterized by a quick, effective and stable stop of bleeding, prevents the development of lymphohemorrhagic complications, and also reduces the frequency of early postoperative complications due to intra- and postoperative laser exposure.

Environmental lead-free Cs3Bi2I9 films deposited by vapor transport deposition for stable all-inorganic solar cells

The non-lead metal halides are of wide interest due to their low toxicity and good stability compared with lead-based perovskites. Among them, Cs3Bi2I9 is of interest because of its excellent electronic and optical properties. In this study, high-quality Cs3Bi2I9 films with large grains and good uniformity were deposited for the first time by a vapor transport deposition (VTD) approach using a mixture of CsI and BiI3 crystal powders as evaporation sources. The Cs3Bi2I9 film was then used as an absorber layer in the solar cell using a superstrate structure with FTO/TiO2/Cs3Bi2I9/CuI/Au. Due to the different melting points of CsI (626 °C) and BiI3 (408 °C), the CsI to BiI3 molar ratio can significantly affect the stoichiometry, structure, and optoelectronic properties of the prepared Cs3Bi2I9 films, which ultimately determine the performance of the Cs3Bi2I9 solar cells. The all-inorganic Cs3Bi2I9 solar cell can achieve a maximum PCE of 1.52% and remain at 80% of its initial value after one month of storage in the air without encapsulation. This work provides a new route to deposit inorganic perovskite films using evaporation sources with different melting points, which has promising applications in solar cells and photodetectors.

КРИСТАЛЛИЗАЦИЯ СТЕКОЛ В РАЗРЕЗЕ Nа2O·2B2O3 — BaO·2B2O3 НАТРИЕВО-БАРИЕВО-БОРАТНОЙ СИСТЕМЫ

The results of crystallization of glass powders of the diborate section of the Na2O BaO B2O3 system are presented. The glass transition temperatures and temperature regions of crystallization at a heating rate of 10 K/min were determined by DTA and XRD methods; the formed crystalline phases were identified, and the nature and temperatures of their melting were established. It is shown that the section under study is not a pseudobinary system, but only a partial section of the sodium-barium borate system. It is shown that the Na2O·2BaO·9B2O3 compound is the phase of primary crystallization in the section; its field covers the majority of the section. The second known ternary compound, Na2O·2BaO·5B2O3, apparently melts peritectically. It has been established that during long-term heat treatment of glasses in a monolithic state, a new phase is formed in them with an approximate composition of Na2O·2BaO·6B2O3.

Enhanced oxidation resistance of single crystal tungsten powder by forming tungsten carbide on the surface

The tungsten-type delay composition is composed of tungsten powder, oxidizing agent and binder, but the tungsten powder will be pre-oxidized after long-term storage, which deteriorates the combustion performance of the tungsten-type delay composition. Therefore, it is necessary to improve the oxidation resistance of tungsten powder. Single crystal tungsten powder (SCTP) is successfully prepared through hydrogen reduction at high temperature and short time, and anti-oxidative single crystal tungsten powder (ASCTP) is obtained by adopting carbonization with a carbon source of gas phase (Carbon monoxide), which enables fuller and more uniform reactions. The TEM results show that the surface of the SCTP is coated by the tungsten carbide, which forms synaptic structures on the surface of the SCTP to protect the SCTP from oxidation by surface modification. As a result, it has been confirmed through TG-DSC tests, oxidation experiments and related electrochemical tests that the oxidation resistance performance of the ASCTP is substantially improved compared with that of the SCTP.

Organosulfur Compound Identified from Striga angustifolia (D. Don) C.J. Saldanha Inhibits Lung Cancer Growth and Induces Apoptosis via p53/mTOR Signaling Pathway.

The Striga angustifolia (D. Don) C.J. Saldanha was used as an Ayurvedic and homeopathic medicine for cancer by the tribal peoples of the Maruthamalai Hills, Coimbatore, India. Hence, the traditional use that has been proven to be effective lacks convincing scientific references. This present study was conducted to investigate the presence of potentially bioactive compounds from S. angustifolia and provides a scientific basis for the ethnobotanical utility. The organosulfur compound 5,5'-dithiobis(1-phenyl-1H-tetrazole) (COMP1) was isolated from S. angustifolia extracts, and the structures of COMP1 were elucidated and characterized by using 13C and 1H nuclear magnetic resonance (NMR) and single crystal X-ray powder diffraction (XRD). Our findings showed that COMP1 significantly reduced cell proliferation of breast and lung cancer cells, but not that of non-malignant epithelial cells. Further analysis revealed that COMP1 promoted cell cycle arrest and apoptosis of lung cancer cells. Mechanistically, COMP1 facilitates p53 activity and inhibits mammalian target of rapamycin (mTOR) signaling, thereby inducing cell cycle arrest and apoptosis of lung cancer cells by inhibiting cell growth. Our findings suggest that COMP1 may serve as a potential drug for lung cancer through the regulation of p53/mTOR pathways.

Synthesis, crystal structure and solution studies of gold(III) complexes with 1,1-dimethylbiguanide

New gold(III) complexes of the composition [Au(dmbgH)Cl2][AuCl4] · H2O and [Au(dmbg)Cl2], where dmbgH is 1,1-dimethylbiguanide and dmbg is deprotonated 1,1-dimethylbiguanide, were synthesized. The resulting compounds were characterized by elemental analysis, IR spectroscopy, 1H NMR spectroscopy, X-ray single crystal and X-ray powder diffraction analyses. In both compounds, 1,1-dimethylbiguanide, regardless of its charge (0 or −1), is bidentately coordinated to gold(III) through the nitrogen atoms of the imino groups. The processes occurring in solutions for the neutral [Au(dmbg)Cl2] complex were studied: the equilibrium of substitution of Cl– by OH– and the redox interaction with glutathione and cysteine in an aqueous solution at t = 25 °C and I = 0.2 M (NaCl).

Efficient Yellow Emission and Near-Unified Photoluminescence Quantum Yield of Sb3+ in a One-Dimensional Confinement Cadmium Chloride Lattice

Sb3+, with a 5s2 electron configuration, has been widely studied as a dopant for its efficient self-trapped exciton (STE) broadband emission. However, the efficient emission of Sb3+-doped one-dimensional (1D) structures and the energy/charge transfer between the host and dopant are rarely reported. In this paper, a series of Sb3+-doped 1D (TDMP)CdCl4 (TDMP = trans-2,5-dimethylpiperazine) powder crystals were prepared by the solvothermal method. The 1D quantum confinement effect and Jahn–Teller distortion in this organic–inorganic hybrid with a soft lattice generate strong electron–phonon coupling. In addition, we also found a fast energy transfer process between the host ([CdCl6]2–) and the dopant ([SbCl6]3–). The synergy of strong electron–phonon coupling and fast energy transfer enables 8.8% Sb3+:(TDMP)CdCl4 to exhibit efficient broadband yellow emission under UV excitation with a photoluminescence quantum yield (PLQY) of 99.69%. DFT calculations indicate that the emission comes from the triplet self-trapped excitons (STEs) emission of the [SbCl6]3– octahedron. This work provides a deeper understanding of the emission of Sb3+ in doped systems and provides a strategy to guide the design of future efficient luminescent materials.

Multi-stimuli, color switchable emitter by solvent induced polymorph synthesis

Polymorphism has drawn great attention in tuning organic solid-state luminescent materials by alteration of molecular packing structure and has considerable potential application in optoelectronic devices and fluorescence sensors. Herein, two polymorphs based on dicyanodistyrylbenzene (DCS) compound were obtained by solvent induced synthesis. We have comprehensively investigated photophysical properties (such as photoluminescence colors, lifetime and PL quantum yield) of the two polymorphs, blue one αDCFDCS (Aqua) and green one αDCFDCS (Green). The single crystal structure analysis and XRD powder pattern shows that there is a slightly packing dislocation in a-axis account for the difference between the two phases. Mechanical grinding can lead to an alternation in photoluminescence color from blue to green. The differential thermal analysis (DTA) measurement discloses αDCFDCS (Aqua) is the metastable state of the compound. Both of two polymorphs show thermochromic and can be reversibly switched upon heating and cooling, which is attributing to the crystal cell expansion with the temperature increasing revealed by in situ XRD. Moreover, fuming with NH3 also causes the color change via Lewis acid base reaction. Upon heating or being exposed to HCl, it will return to the original state. The results of the polymorphism not only provide an insight into molecular packing and emission properties, but also pave the way for understanding the solid luminescence change by the multi-stimuli response.

Modification of UHPC Matrix and Fiber Surface for Improving the Mechanical Performance of Ultra-High-Performance Fiber-Reinforced Concrete

In this study, filler and silica fume were substituted by Liquid crystal display glass powder (LCDGP) and nanosilica, respectively, to improve the performance of ultra-high- performance fiber-reinforced concrete. In addition, the surface of steel fiber was modified with ethylenediaminetetraacetic acid (EDTA) solution to improve the interfacial friction between the fiber and Ultra-high-performanceconcrete (UHPC) matrix. Both LCDGP and nanosilica reacted with calcium hydroxide to form hydrates, and the fiber surface roughness increased owing to the EDTA treatment. When LCDGP was used, the compressive strength decreased owing to a decrease in packing density; however, the compressive and tensile strengths of Ultra-high-performance fiber-reinforced-concrete (UHPFRC) were improved on using nanosilica. It was observed that the surface modification of the fiber increased the friction force between the UHPC and fiber interface; therefore, it was more effective in improving the tensile strength than the compressive strength.

Direct Imaging of Band Structure for Powdered Rhombohedral Boron Monosulfide by Microfocused ARPES.

Boron-based two-dimensional (2D) materials are an excellent platform for nanoelectronics applications. Rhombohedral boron monosulfide (r-BS) is attracting particular attention because of its unique layered crystal structure suitable for exploring various functional properties originating in the 2D nature. However, studies to elucidate its fundamental electronic states have been largely limited because only tiny powdered crystals were available, hindering a precise investigation by spectroscopy such as angle-resolved photoemission spectroscopy (ARPES). Here we report the direct mapping of the band structure with a tiny (∼20 × 20 μm2) r-BS powder crystal by utilizing microfocused ARPES. We found that r-BS is a p-type semiconductor with a band gap of >0.5 eV characterized by the anisotropic in-plane effective mass. The present results demonstrate the high applicability of micro-ARPES to tiny powder crystals and widen an opportunity to access the yet-unexplored electronic states of various novel materials.

Boosting the Piezoelectric Sensitivity of Amino Acid Crystals by Mechanical Annealing for the Engineering of Fully Degradable Force Sensors.

Biodegradable piezoelectric force sensors can be used as implantable medical devices for monitoring physiological pressures of impaired organs or providing essential stimuli for drug delivery and tissue regeneration without the need of additional invasive removal surgery or battery power. However, traditional piezoelectric materials, such as inorganic ceramics and organic polymers, show unsatisfactory degradability, and cytotoxicity. Amino acid crystals are biocompatible and exhibit outstanding piezoelectric properties, but their small crystal size makes it difficult to align the crystals for practical applications. Here, a mechanical-annealing strategy is reported for engineering all-organic biodegradable piezoelectric force sensors using natural amino acid crystals as piezoelectric materials. It is shown that the piezoelectric constant of the mechanical-annealed crystals can reach 12 times that of the single crystal powders. Moreover, mechanical annealing results in flat and smooth surfaces, thus improving the contact of the crystal films with the electrodes and leading to high output voltages of the devices. The packaged force sensors can be used to monitor dynamic motions, including muscle contraction and lung respiration, in vivo for 4weeks and then gradually degrade without causing obvious inflammation or systemic toxicity. This work provides a way to engineer all-organic and biodegradable force sensors for potential clinical applications.

Molecular γ-amino butyric acid and its crystals: Structural, electronic and optical properties

This work presents the formation of monoclinic γ-aminobutyric acid (GABA) crystals grown from an aqueous ethanol solution with the dimensions 4 ​× ​1 ​× ​0.6 ​mm3. The structural properties of the grown crystal were evaluated via X-ray diffraction analysis of the powder and single crystal, which confirmed a monoclinic crystal system with space group P21/c. Thermal stability and the melting point of the synthesized GABA crystal were investigated using TG-DSC measurements. We also characterized experimentally monoclinic and molecular GABA solvated in water, obtaining its optical absorption spectrum in the UV-VIS region. Time-dependent DFT calculations were performed for the GABA molecule in the neutral and zwitterion forms to understand their optical absorption features. Structural, electronic, and optical properties of four γ-aminobutyric acid (GABA) crystal polymorphs (monoclinic, tetragonal, hexagonal, and monohydrate) were achieved through DFT calculations employing a dispersion corrected exchange-correlation functional. Differences in the electronic and optical properties between polymorphs are discussed. We predict the GABA monoclinic crystal to be an indirect gap semiconductor with a gap value of 5.02 ​eV, in good agreement with our experimental measurements. Considering the other three polymorphs, their fundamental gap values range from 4.6 ​eV to 5.16 ​eV (being direct for all of them, except the monohydrate). The absorption spectra calculations reveal a significant optical anisotropy for all GABA crystals, with the highest optical absorption for the monoclinic structure in the 5–6 ​eV energy range.

A combination of liquid–crystal display glass powder and slag in alkali-activated material

This study presents the feasibility of a combination of liquid–crystal display glass powder (LCDGP) and slag in alkali-activated materials using several techniques including nuclear magnetic resonance and thermodynamic modeling. Slag was replaced with LCDGP at a weight ratio of 25%, 50%, 75%, and 100%. Replacing slag with LCDGP up to 50% resulted in no strength loss and no significant changes in phase assemblages compared to alkali-activated slag. The incorporation of 25% LCDGP improved the pore structure and the reactivity of both precursors which result in increased compressive strength. This was because aluminum of LCDGP incorporated into the silicate which polymerized more C-(N)-A-S-H gel. However, the excessive use of LCDGP (more than 50%) caused a significant strength loss. Since LCDGP was responsible for lowering the pore solution’s pH, its excessive use reduced the reactivity of precursors and caused a significant strength loss. This study suggests a guideline for using LCDGP to improve the mechanical property of alkali-activated slag.

Synthesis of MnSi1.7 nanosheet bundles from CaSi2 crystal powders using MnCl2 in molten salt

MnSi1.7 nanosheet bundles with an improved homogeneous composition were synthesized by annealing from CaSi2 crystal powders with MnCl2 in molten salt. The MnSi and Si phases were formed at the initial stage of the synthesis with an inhomogeneous Mn distribution within the nanosheet bundles. Subsequently, the phases were transformed into MnSi1.7 with an improved homogeneous Mn distribution within them for 10 h annealing in the molten salt. The formation of multiple Mn-silicide phases and remarkable improvement in the structural homogeneity of the MnSi1.7 nanosheet bundles were discussed in terms of the reactions of Mn or Si with chloride compounds, decomposition of chlorides at elevated temperatures, phase selection of multiple silicide phases, shrinkage of the volume from Si to MnSi1.7, and dominant diffusion species. Multiple growth variants of the MnSi1.7 domains were stacked in the nanosheets. For comparison, the growth in a deliquescent environment realized by NH4Cl addition was examined.

Crystal structure and X-ray powder diffraction data for ruxolitinib

X-ray powder diffraction data, unit-cell parameters, and space group for ruxolitinib are reported [a = 8.7211(5) Å, b = 19.6157(15) Å, c = 18.9645(10) Å, β = 90.903(6)°, unit-cell volume V = 3243.85 Å3, Z = 8, and space group P21]. All measured lines were indexed and are consistent with the corresponding space group. No detectable impurities were observed. The single-crystal data of ruxolitinib are also reported [space group P21, a = 8.7110(2) Å, b = 19.5857(4) Å, c = 18.9372(4) Å, β = 90.8570(10)°, unit-cell volume V = 3230.53(10) Å3, Z = 8]. The experimental powder diffraction pattern has been well matched with the simulated pattern derived from the single-crystal data.

Efficiency enhancement of Cu2ZnSnS4 monograin layer solar cells via absorber post-growth treatments

Currently, the efficiency of Cu 2 ZnSnS 4 (CZTS) monograin layer solar cells is mainly limited by the recombination losses in the bulk and at the surface of absorber/buffer that need to be reduced. One approach to significantly improve the performance of CZTS monograin layer solar cells is to post-treat the surfaces of monograin powder crystals before the buffer layer deposition. This study includes the optimization of two sequential post-treatment steps: 1) chemical etching of as-grown powder crystals with Br 2 in methanol followed by KCN; and 2) annealing at different temperatures (550–850 °C) under different sulfur vapor pressures (100–2050 Torr) in a two-temperature zone furnace in closed ampoules. Energy-dispersive X-ray spectroscopy, high-resolution scanning electron microscopy and Raman studies using multiwavelength excitation revealed that SnS 2 and ZnS secondary phases were formed on the crystals’ surfaces in the thermal annealing process. At the same time, by increasing the annealing temperature, the ratio of Cu/(Zn + Sn) increased and Zn/Sn decreased in the bulk of annealed CZTS crystals compared to as-grown monograin powder crystals. Optimal conditions for combinational post-treatment to adjust the absorber material composition and to improve monograin layer solar cells' performance were found as follows: the chemical etching of as-grown powders with 1% Br 2 –MeOH for 5 min + 10% KCN for 5 min followed by annealing in sealed ampoules at 850 °C in a sulfur atmosphere of 2050 Torr for 1 h. The highest power conversion efficiency of 9.44% was obtained under these conditions. • Optimal conditions for combinational post-treatment of CZTS crystals were found. • The content of Cu ↑ and Zn ↓ in the bulk of CZTS crystals by increasing annealing temperature. • The formation of SnS 2 flakes on crystals surfaces in the annealing process was determined. • The PCE of CZTS solar cells enhanced from 3.8% to 9.44% by optimizing post-treatment conditions.

A new series of magnetic and luminescent layered hybrid materials obtained from thianthrene phosphonic acid: M(H2O)PO3-S2C12H7 (M = Cu, Zn) and M(H2O)2(PO2OH-S2C12H7)2 (M = Mn, Co).

Four new metallophosphonates with the chemical formulae M(H2O)PO3-S2C12H7 (M = Cu, Zn) and M(H2O)2(PO2OH-S2C12H7)2 (M = Mn, Co) were synthesized using a hydrothermal route from the original bent rigid thianthrene-2-ylphosphonic acid (TPA). This organic precursor crystallizes in a non-centrosymmetric space group P212121 and presents a unique bent geometry due to the presence of two sulfur atoms in its rigid platform architecture. Obtained as single crystal and polycrystalline powders, the structures of the four hybrid materials were solved using X-ray diffraction on single crystals in a monoclinic P21/c space group. These compounds adopt a lamellar structure consisting of one inorganic subnetwork alternating with a 'sawtooth' double organic -S2C12H7 subnetwork. The inorganic layers of these compounds are made of (PO3C) or partially deprotonated (PO2OHC) tetrahedra connected by the apices to isolated ZnO3(H2O) tetrahedra, Cu2O6(H2O)2 copper dimers and cobalt and manganese MO4(H2O)2 octahedra, where the latter two exhibit an isotype structure. Thermogravimetric analysis was performed to confirm the amount of water molecules present in the formula, to track the dehydration process of the structures, and to evaluate their thermal stability. The magnetic properties of the copper, cobalt, and manganese-based materials were investigated from 2 K to 300 K by using a SQUID magnetometer revealing dominant antiferromagnetic interactions with Weiss temperatures of -8.0, -10, and -1 K, respectively. These magnetic behaviors were further corroborated by first-principles simulations based on Density Functional Theory (DFT). Finally, the absorption and photoluminescence properties of both the ligand and hybrid materials were investigated, revealing diverse excitation and recombination mechanisms. The organic moiety based on thianthrene significantly influenced the absorption and emission, with additional peaks attributed to transition metals. Singlet and triplet states recombination were observed, accompanied by an unidentified quenching mechanism affecting the triplet state lifetime.

Influence of alkali iodide fluxes on Cu2ZnSnS4 monograin powder properties and performance of solar cells

The successful synthesis-growth of monograin powders in alkali iodide salts (NaI, KI, RbI, CsI) has been demonstrated. These powders are potentially usable as absorber materials in flexible solar panels based on monograin layer solar cell technology.

SINTESIS DAN UJI AKTIVITAS ANTIBAKTERI SENYAWA TURUNAN AMOKSISILIN TERHADAP Escherichia coli

Amoxicillin derivate compounds from the reaction of amoxicillin with p-aminophenol are synthesized compounds by reacting amoxicillin and p-aminophenol. . Escherichia coli is a flora normal bacteria that can causing infectious diseases. This research aimed to determine the antibiotic activity of amoxicillin derivat compound (amoxicillin with p-aminophenol) on the growth of E. coli. This research was conducted using the disc diffusion method. amoxicillin derivat compound (amoxicillin with p-aminophenol) were characterized by organoleptic test, melting point determination, pH test determination, Rf value, and maximum wavelength. The results of the organoleptic test showed that amoxicillin derivates from amoxicillin and p-aminophenol reaction is crystal powder, dark brown and bit bitter. Melting point of amoxicillin derivates from amoxicillin and p-aminophenol reaction was 160ºC. pH test of amoxicillin derivates from amoxicillin and p-aminophenol reaction was 6,5. Rf value of amoxicillin derivates from amoxicillin and p-aminophenol reaction was 0,79. The results of UV wavelength scanning showed that amoxicillin derivates from amoxicillin and p-aminophenol reaction at 295 nm. Antibiotic activity showed by the clear zone form around the paper disk. The results showed that E. coli was resistant to pure amoxicillin. Amoxicillin derivat compound (amoxicillin with p-aminophenol) with concentrations of 100% and 12,5% have the largest inhibitory zones (6,33 mm) compared with concentrations of 50% and 25%, 5,33 and 6,00 mm respectively. Based on these results it can be concluded that derivat compound of amoxicillin (amoxicillin with p-aminophenol) has antibiotic activity against the growth of E. coli that has been resistant to pure amoxicillin.

Chemical conversion of CO2 into cyclic carbonates by two Metal–Organic frameworks

Two metal–organic frameworks (MOFs), DDCu and DDMn have been synthesized from a tetracarboxylate ligand by solvothermal method. DDCu contained paddlewheel- [Cu2(COO)4] clusters with axial sites occupied by water molecules and comprised of two types of cages: smaller spherical cages of diameter 9.3 Å and larger ellipsoidal cages of dimensions of 12.4 × 17.7 Å2. While DDMn having bimetallic Mn2(COO)4 clusters with 1D rhombus channels of window size 10.16 × 8.97 Å2. Both the MOFs have open framework structure with solvent accessible void volume 66.5 % and 64.1 % based on the PLATON calculations. The MOFs have been characterized by a series of methods like Single crystal XRD, powder XRD, FT-IR, TGA and N2 adsorption study. Brunauer−Emmett−Teller (BET) surface area of the activated MOFs were 360 and 290 m2/g, respectively. The loosely bound water molecules could be removed to produce unsaturated metal coordination sites that rendered exciting heterogeneous catalytic properties at the metal center of DDCu and DDMn in the fixation of CO2 through the cycloaddition of CO2 with various epoxide. Under ambient conditions (25 °C and 1 atm. CO2 pressure), both the catalyst showed appreciable yields (96 and 91 %) and selectivity (>99 %) for cyclic carbonate formations. Both the catalysts showed very good recycling properties (at least five times).