Small Cavity Research Articles

Thermodynamic Feasibility of the Black Sea CH4 Hydrate Replacement by CO2 Hydrate

There is an international consensus that reductions of CO2 emissions are needed in order to reduce global warming. So far, underground aquifer storage of CO2 is the only commercially active option, and it has been so since 1996, when STAOIL started injecting a million tons of CO2 per year into the Utsira formation. Storage of CO2 in the form of solid hydrate is another option that is safer. Injection of CO2 into CH4 hydrate-filled sediments can lead to an exchange in which the in situ CH4 hydrate dissociates and releases CH4. Two types of additives are needed, however, to make this exchange feasible. The primary objective of the first additive is related to hydrodynamics and the need to increase injection gas permeability relative to injection of pure CO2. This type of additive is typically added in amounts resulting in concentration ranges of additive in the order of tens of percentages of CO2/additive mixture. These additives will, therefore, have impact on the thermodynamic properties of the CO2 in the mixture. A second additive is added in order to reduce the blocking of pores by new hydrates created from the injection gas and free pore water. The second additive is a surfactant and is normally added in ppm amounts to the gas mixture. A typical choice for the first additive has been N2. The simple reasons for that are the substantial change in rheological properties for the injection gas mixture and a limited, but still significant, stabilization of the small cavities of structure I. There are, however, thermodynamic limitations related to adding N2 to the CO2. In this work, we discuss a systematic and consistent method for the evaluation of the feasibility of CO2 injection into CH4 hydrate-filled reservoirs. The method consists of four thermodynamic criterions derived from the first and second laws of thermodynamics. An important goal is that utilization of this method can save money in experimental planning by avoiding the design of CO2 injection mixtures that are not expected to work based on fundamental thermodynamic principles. The scheme is applied to hydrates in the Black Sea. Without compositional information and the knowledge that there is some verified H2S in some sites, we illustrate that the observed bottom hydrate stability limits are all with hydrate stability limits of hydrates containing from 0 to 3 mole% H2S. A limited number of different injection gas mixtures has been examined, and the optimum injection gas composition of 70 mole% CO2, 20 mole% N2, 5 mole% CH4, and 5 mole% C2H6 is feasible. In addition, a surfactant mixture is needed to reduce blocking hydrate films from injection gas hydrate.

Front Cover: Brønsted Acid/Base Site Isolated in a Pentanuclear Scaffold (Chem. Eur. J. 7/2023)

H+ that exists in its thermodynamically metastable state is reported. The key to success was to employ a metal-complex-based scaffold with a small cavity within its structure. By sterically isolating Brønsted acid/base sites, anomalous behaviors of H+ were observed. In addition, the unique physical and chemical properties of the isolated sites were clarified. More information can be found in the Research Article by S. Masaoka and co-workers. (DOI: 10.1002/chem.202203253).

Examine the lattice Boltzmann method for the mixed convection simulation of water/Al2O3 nanofluid in a 2D rectangular cavity under radiation with isothermal semicircular obstacles

The present study simulated the mixed convection (MCXN) of the water/Al2O3 nanofluid (NFs) in a two-dimensional rectangular cavity in the presence of radiation. The top and bottom walls were assumed to be cold and hot, respectively, with the lateral walls being insulated. A magnetic field (MGF) with a Hartmann number (Ha) of 0–40 was applied to the NFs within the cavity. The simulations were carried out at a Richardson number (Ri) of 1 and a Rayleigh number (Ra) of 105 for cavity heights of 0.5–2.0 to evaluate heat transfer (HTF) on the walls and analyze fluid rotation within the cavity. The lattice Boltzmann method (LBM) was used to perform the simulations. It was found that the incorporation of radiation into the system reversed the flow rotation in the cavity and increased the Nu. A rise in the radiation parameter from 0 to 0.2 led to a 2.8-fold larger Nu on the cold wall. A rise in the cavity height decreased the Nu, and a further increase in the height increased the Nu on the wall. An increased Ha had an insignificant effect on the Nu at small cavity heights but decreased the Nu on the wall at large cavity heights.

A call for nail clipping histopathology to become an essential component of the routine evaluation of melanonychia: Benefitting patients as a triage and surgical planning maneuver.

We call on dermatologists and dermatopathologists to include nail clipping histopathology as an essential component of the routine evaluation of melanonychia. This manuscript demonstrates a case where an adult woman with broad melanonychia of the right thumbnail declined a nail matrix biopsy, but was amenable to a nail clipping.The nail clipping showed pigmentation, melanocyte remnants, and small cavities in the nail plate. These features have been published previously by our group as a clue to nail unit melanoma within nail clippings.This patient was rapidly triaged for nail matrix biopsy, which demonstrated nail unit melanoma in situ. Every patient with melanonychia can benefit from a nail clipping by examination of the location of the pigmentation within the nail plate for surgical planning, and if melanocyte remnants are detected, the nail clipping also serves as a rapid triage mechanism for nail matrix biopsy to evaluate for nail unit melanoma. Fontana-stained sections will highlight the pigmentation in the nail plate, and its location in the nail plate can easily be described by the dermatopathologist. Nail clippings performed in the setting of clinically apparent melanonychia may show helpful histopathologic findings of pigmented fungi, hemorrhage, external pigmentation, features of other pigmented nail unit tumors, as well as other entities. Nail clipping histopathology can provide extensive information in the evaluation of melanonychia with minimal discomfort for a patient, and little disruption to a physician's clinic flow. With this additional case of a nail unit melanoma diagnosed after initial concern found in a nail clipping, as well as other information in the literature, it is clear that melanocyte remnants found in nail clippings are reliable concerning features related to nail unit melanoma in adults. With knowledge of these histopathologic features in nail clippings and the significance of melanocyte remnants, the dermatopathologist can play a crucial role in the use of a nail clipping as a life-saving diagnostic maneuver. Accordingly, given the potential benefit to patients in this setting, as well as other uses of a nail clipping in the evaluation of melanonychia, we call on dermatologists and dermatopathologists to innovate the routine evaluation of melanonychia through the routine employment of nail clippings for histopathologic evaluation.

High-resolution micro-cavity filling sensing by fiber optic interferometry.

In the last decade, new potential applications of micro- and nano-products in telecommunication, medical diagnostics, photovoltaic, and optoelectronic systems have increased the interest to develop micro-engineering technologies. Injection molding of polymeric materials is a recent method being adapted for serial manufacturing of optic components and packaging at the micro- and nano-scale. Quality assurance of replication into small cavities is an important but underdeveloped factor that is needed to ensure high production efficiency in any micro-fabrication industry. In this work, we introduce a fiber-based interferometric measurement sensor to monitor the cavity filling of optical microstructures fabricated into a macroscopic molding die. The interferometer was capable of resolving melt front motion into the microcavity to the point of complete filling as verified by atomic force microscopy. Despite the low reflectivity of the transparent polymer and unoptimized reflected light collection optics, this system is capable of monitoring polymer movement during the course of filling and detecting the completion of the process. The simplicity and flexibility of the technology could allow eventual instrumentation of injection molds, embossing, and nanoimprint tooling suitably modified with a small optical window to accommodate light from an optical fiber. This would provide a solution to the challenging problem of monitoring local, nanometer scale filling processes.

Evaluation of the effect of partial hydrolysis ethyl cellulose on physicochemical properties of soybean oil oleogel

SummaryThe effects of the solvent composition of ethanol and acetic acid (50/50 and 70/30 v/v), time (30 and 60 min) and temperature (65 and 95°C) of hydrolysis were conducted on the structural and physicochemical properties of ethyl cellulose (EC). Differential scanning calorimetry (DSC) and capillary viscometer results revealed that EC hydrolysis significantly decreased glass transition temperature (Tg) and intrinsic viscosity. FTIR spectra of hydrolysed EC (H‐EC) revealed a breakdown of many glycosidic bonds. The oleogels were prepared by H‐EC at the concentration of 6 wt%. Results showed that hydrolysis conditions significantly affected oleogel formation and strength. An optimal oleogel structure was achieved with H‐EC at 65°C, 50/50 solvent ratio (H‐EC65/50). The rheological analysis of H‐EC65/50 oleogel showed higher strength and a lower melting temperature range than EC oleogel. Microscopic observations confirmed that the H‐EC65/50 forms a new structure with many small cavities, probably the main reason for the firmer gel. The prepared formulation could have potential to prepare reduced fat formulations with the suitable melting point and texture.

Напрямки оптимізації розвідки і розроблення нафтових родовищ Західного Причорномор’я України

The southern part of the Dobrogea Foredeep is located in the southwestern regions of Ukraine within the Odesa region. Here, on the territory of the uplifted Bilolissya block, the East Sarata, Zhovtyjar, Saryjar, Zarichna oil accumulations are located in the chemogenic-carbonate layer of the Middle and Upper Devonian. The deposits are confined to limestones and dolomites with secondary fractured-cavernous-porous reservoirs. They lie at depths of 2500–3200 m. During the test of two dozen wells, the filtrate of the drilling fluid with a small amount of oil was received with the estimated flow rates of several tons per day. The rise of the oil level in the wells was quickly stopped, the hydrodynamic connection of the wells with the productive formations was lost. The use of today's known methods of intensification of the flow of hydrocarbon fluids did not lead to positive results. According to the research of microphotographs of reservoir rocks, it is proved that the largest voids of reservoir rocks are filled with immobile bitumen, while the smaller cavities contain mobile oil. Immobile bitumen fills main channels and blocks communication between rock cavities. This is the main reason for the absence of industrial inflows of oil to the wells. Another important reason is the low filtering properties of the collectors. Most of them have a permeability of less than 0.01∙μD. Other reasons for the failure of the industrial development of oil deposits are the high dynamic viscosity of oil due to the high content of asphaltenes, silicagel resins, paraffins, the low energy potential of oil deposits due to their degassing during the long geological time, as well as the lack of hydrodynamic connection of oil deposits with natural water pressure systems. We assume that the Middle and Upper Devonian oil fields of the Western Fore-Black Sea area are most likely mainly bituminous. Given the significant depths of the deposits, their industrial development is technically impossible today. Therefore, it is impractical to plan further scientific research on the mentioned complex. Instead, research should be reoriented to the Silurian terrigenous-carbonate complex and the Lower Devonian terrigenous complex, which are hydrodynamically more closed and in which non-degassed hydrocarbon accumulations can be preserved.

The Development of the Acoustic Capnometer

We developed an acoustic capnometer to estimate the partial pressures of arterial carbon dioxide from expired air in the pulmonary rehabilitation devices for patients with respiratory failure. Because partial pressures of carbon dioxide reduce the velocity of sound propagating through expired air, we developed an acoustic capnometer. The present study proposes a unique method based on the measurement of acoustic velocity in expired air, thus eliminating the use of a specific carbon dioxide sensor. The current method can fabricate the capnometer at an appreciably low cost, enabling the device to be used for various rehabilitation purposes. The acoustic capnometer comprises a cylindrical small sample cavity, an ultrasonic transmitter-receiver system, electronic circuits for velocity determination, and a microprocessor for data processing. To validate the device, 12 patients with pulmonary disease were enrolled, and end-tidal partial pressures of carbon dioxide obtained from the current device were compared to the carbon dioxide tension measured by conventional arterial blood gas analysis. The results show a linear relationship in the region of interest (40–60 torr). Therefore, the proposed device facilitates the estimation arterial carbon dioxide partial pressures without sampling blood.

Патогенетические механизмы развития деструктивной пневмонии у детей. Клиническое наблюдение с обзором литературы

Destructive pneumonia (DP) in children is a complication derived from community-acquired pneumonia, while parenchymal necrosis occurs in the pulmonary infiltration zone with the formation of multiple merging small cavities. The disease pathogenesis has not yet been precisely established. The factors predisposing to pulmonary destructive complications in pneumonia remain unknown. We present a case study of this disease in a 5-year-old female patient hospitalized in December 2022. Manifestation in the form of acute upper respiratory tract infection, subsequent deterioration with the progression of pneumonia and pleurisy indicate the importance of viral-bacterial interactions in the DP pathogenesis. Influenza A was confirmed in the laboratory, while Streptococcus pneumoniae was isolated in the fluid culture obtained during bronchoalveolar lavage. Using the example of the presented case, we discuss the mechanisms of DP pathogenesis in children from a modern perspective. The necessity of coagulology, a combination of radiology diagnostic methods (radiography, ultrasound, computed tomography) was justified. It is necessary to further study the pathogenetic mechanisms of the DP progression in order to optimize preventive and therapeutic rehabilitation measures in community-acquired pneumonia in children. KEYWORDS: destructive pneumonia, necrotizing pneumonia, influenza A, Streptococcus pneumoniae, hypercoagulation. FOR CITATION: Tolstova E.M., Besedina M.V., Zaytseva O.V., Zaitseva N.S., Yatsyshina S.B., Khaspekov D.V., Olkhova E.B., Turishchev I.V., Sholokhova N.A., Galeev P.P., Belyaeva T.Yu. Pathogenetic mechanisms of destructive pneumonia in children. Case report with literature review. Russian Journal of Woman and Child Health. 2023;6(3):310–319 (in Russ.). DOI: 10.32364/2618-8430-2023-6-3-15.

Minimally invasive treatment of a giant pancreatic pseudocyst

The authors present minimally invasive treatment of a giant infected pancreatic pseudocyst. Throughout in-hospital period, the patient underwent endosonography-guided transgastric drainage of the pseudocyst, 7 endoscopic debridement of the cavity with sequestrectomy, laparoscopy for enzymatic peritonitis and external percutaneous drainage of the pseudocyst. Effectiveness of minimally invasive treatment was assessed considering laboratory data (CRP, white blood cell count), clinical data (hyperthermia, complaints) and follow-up ultrasound and computed tomography data (cyst dimension, sequestration). We observed with positive dynamics with decrease of intoxication syndrome, serum CRP and white blood cell count after two debridement procedures. After the seventh endoscopic debridement and sequestrectomy, granulations occurred in the cyst cavity and there was no further sequestration. At discharge, CT revealed dry residual small cavity 1.5×3 cm. There were no any complaints.

Numeričko ispitivanje pojedinačnih i višestrukih udara sintetičkih mlazova na polje protoka i prenos toplote na malim rastojanjima između otvora i ploče

In the present numerical study, the thermal performance and fluid flow properties have been investigated to show the effect of single-orifice and multiple-orifice impingement of synthetic jets for dimensionless orifice-toplate distance (H/D) of lower than one. Investigations have been done for an actuation frequency of f=500 Hz, 0.10 ≤ H/D ≤ 0.75, and dimensionless pitch ratio of 1.25 ≤ Do/D ≤ 1.75. The results were validated with experimental results from the literature, and a fair agreement was obtained. The results showed that at low nozzle-to-plate spacing, lower target plate temperatures could be obtained. It was observed that with the use of multiple orifices at especially higher Do/D higher heat transfer values are present. The study was performed to add knowledge to the electronics and aviation industries where high temperatures in small cavities occur.

Molecular interaction between xanthorrhizol with ghrelin-o-acyl transferase (goat) and growth hormone SECRETAGOG3UE receptor (GHS-R): a docking analysis

After curcuminoids, xanthorrhizol is the second primary bioactive compound from Curcuma xanthorrhiza. Traditionally, the rhizome of Curcuma xanthorriza is well-known for its appetite stimulation. However, the mechanism of appetite stimulation is still unclear, particularly its interaction with the appetite-related ghrelin system. Therefore, understanding interactive molecular modulations of xanthorrhizol with ghrelin, GOAT (ghrelin-O-acyl transferase), and ghrelin receptor (GHS-R: growth hormone secretagogue receptor is essential. Xanthorrhizol, an appetite stimulant, may interact with ghrelin, GOAT, and GHS-R. Herein, this study aimed to do in silico analysis to hypothetically predict the molecular interaction of xanthorrhizol with ghrelin, ghrelin-O-acyl transferase (GOAT), and growth hormone secretagogue receptor (GHS-R). Docking analysis was conducted to understand the interactive molecular patterns of xanthorrhizol, ghrelin, GOAT, and GHS-R. The docking studies showed that the molecular interaction of xanthorrhizol is with Arg10 of ghrelin and not with Ser2, which is essential for the linkage of octanoic acid. The molecular interaction of xanthorrhizol with GOAT is in the active sites of either deacylated ghrelin or octanoic acid. Therefore, xanthorrhizol is a competitive inhibitor of GOAT. It inhibits GOAT activity. Xanthorrhizol interacts with GHS-R in its small cavity II. Itnis still unclear whether this interaction is agonist or antagonist. This in silico analysis showed that xanthorrhizol is probably not a stimulating appetite natural drug via stimulating GHS-R signaling.

Transition of Standard Dosimetry of Absorbed Dose to Water in External Beam Radiotherapy [Part 1]

The radiotherapy is performed with the aim of delivering the optimal dose to the target volume with minimal side effect of surrounding normal tissue. For this purpose, quality assurance is essential to ensure that the target volume is correctly irradiated in the optimal geometrical arrangement, and the absorbed dose evaluation is essential to ensure that the prescribed dose is correctly delivered. The absorbed doses are generally evaluated using a small cavity ionization chamber that utilizes gas ionization. For the evaluation of absorbed dose to water using ionization chambers, the national dose and charge standards, ionization chambers and electrometer calibration systems are required. And it is also required standard dosimetry protocol that recommend conditions such as fields, depths, and optimal ionization chambers for the measurement, as well as reliable physical data. This manuscript reviews the transition of standard dosimetry of absorbed dose to water in external beam radiotherapy, including the background of dose standards, ionization chamber calibration systems, units, and physical constants.

Surgical Approaches to Cavernous Sinus: A Narrative Review of the Literature with Anatomical Drawings.

IIntroduction. The cavernous sinus (CS) is a paired venous sinus in the human brain that is classified as a true dural venous sinus rather than a venous plexus. The entire CS is separated by septa into two small cavities called caves. The CS has a very close resemblance to various key structures present in the head. The CS is a blood compartment that contains ligaments, endothelium, and trabeculae. It is clinically significant because of its position and relationship with several cranial nerves. Clinical implications. For effective management and treatment of CS syndrome, CS thrombosis, carotid-cavernous fistula, and other CS-related problems, CS surgery became necessary. As a result of the lack of sophisticated surgical techniques in the past, CS surgery was exceedingly challenging, complicated, and deadly. The surgery of CSs can benefit from a variety of surgical procedures, including extradural and intradural, endoscopic endonasal, rhomboid, and temporopolar trans cavernous approaches. In this review, numerous surgical procedures for CS are discussed along with their intended uses. Conclusions. A greater understanding of the CS was made possible by the quick modifications and improvements in surgical methods, which aided in neurosurgery procedures.

Embedding Group VIII Elements into a 2D Rigid pc-C3N2 Monolayer to Achieve Single-Atom Catalysts with Excellent OER Activity: A DFT Theoretical Study

Under DFT calculations, a systematic investigation is carried out to explore the structures and oxygen evolution reaction (OER) catalytic activities of a series of 2D single-atom catalyst (SAC) systems, which are constructed by doping the transition metal (TM) atoms in group VIII into the cavities of rigid phthalocyanine carbide (pc-C3N2). We can find that when Co, Rh, Ir and Ru atoms are doped in the small or large cavities of a pc-C3N2 monolayer, they can be used as high-activity centers of OER. All these four new TM@C3N2 nanostructures can exhibit very low overpotential values in the range of 0.33~0.48 V, even smaller than the state-of-the-art IrO2 (0.56 V), which indicates considerably high OER catalytic activity. In particular, the Rh@C3N2 system can show the best OER performance, given that doped Rh atoms can uniformly serve as high-OER-active centers, regardless of the size of cavity. In addition, a detailed mechanism analysis was carried out. It is found that in these doped pc-C3N2 systems, the number of outer electrons, the periodic number of doped TM atoms and the size of the embedded cavity can be considered the key factors affecting the OER catalytic activity, and excellent OER catalytic performance can be achieved through their effective cooperation. These fascinating findings can be advantageous for realizing low-cost and high-performance SAC catalysts for OER in the near future.

Khurayyimite Ca7Zn4(Si2O7)2(OH)10·4H2O: a mineral with unusual loop-branched sechser single chains

The new mineral khurayyimite Ca7Zn4(Si2O7)2(OH)10·4H2O occurs in colorless spherulitic aggregates in small cavities of altered spurrite marbles located in the northern part of the Siwaqa pyrometamorphic rock area, Central Jordan. It is a low-temperature, hydrothermal mineral and is formed at a temperature lower than 100 °C. Synchrotron single-crystal X-ray diffraction experiments have revealed that khurayyimite crystallizes in space group P21/c, with unit cell parameters a = 11.2171(8), b = 9.0897(5), c = 14.0451(10) Å, β = 113.297(8)º, V = 1315.28(17) Å3 and Z = 2. The crystal structure of khurayyimite exhibits tetrahedral chains of periodicity 6. The sequence of SiO4 and ZnO2(OH)2-tetrahedra along the chain is Si–Si-Zn. The neighboring SiO4-tetrahedra of the corrugated chains are bridged by additional ZnO2(OH)2-tetrahedra to form 3-connected dreier rings. The chains can be addressed as loop-branched sechser single chains {lB, 11∞}[6Zn4Si4O21]. The chains are linked by clusters of five CaO6 and two CaO7 polyhedra with additional OH groups and H2O molecules in the coordination environment. Based on the connectedness and one-dimensional polymerisations of tetrahedra (TO4)n−, chains of khurayyimite belong to the same group as vlasovite Na2ZrSi4O11, since they can be described with geometrical repeat unit cTr = 2T43T4 and topological repeat unit cVr = 2V23V2.

Recent advancements in femtosecond laser inscribed waveguides in germanate glass for ∼ 2.1 µm laser applications

The realization and integration of high-power and high-speed microscale functionalities on a single chip have been made possible through the revolutionizing field of Photonics. This next generation monolithic technology emphasizes on efficient and cost-effective fabrication of the miniaturized photonic devices with high degree of accuracy. For such monolithic devices small cavity, single frequency laser sources (waveguide lasers) are of immense importance. Multiple techniques have been utilized for the inscription of waveguides in the laser gain media. Femtosecond laser direct writing (FLDW) is an emerging technique for rapid inscription of highly symmetrical and high-quality 3D guiding structures in substrates with low propagation loss. In this article, we present a review on the latest developments around femtosecond laser inscribed waveguides in an emerging germanate glass (in contrast to the commercially available and exotic transparent media) for short to mid-IR laser applications.

Clinical substantiation of the use of connective tissue graft transplantation technique as a surgical stage for deepening the oral cavity opening in the treatment of periodontitis

The aim of the work was to evaluate the effectiveness of vestibuloplasty with free gingival graft transplantation in patients with small oral cavity opening in the treatment of severe periodontitis.
 The study group consisted of 14 patients who, in the period from 2020 to 2022, on the basis of the Department of Maxillofacial Surgery of the RUDN, 14 operations were performed to deepen the vestibule of the oral cavity with the insertion of a free graft from the palate. The measurements were carried out before and 6 months after the surgical treatment with a graduated periodontal probe, the surgical operation was preceded by a conservative stage of treatment.
 Following the results of the vestibuloplasty operation, the depth of the vestibule in the study group increased by an average of 3.63 times (from 1.32 to 5.06 mm). An increase in the depth of the vestibule of the oral cavity was observed in all cases of treatment.
 The conclusion is made about the effectiveness of using this technique in the treatment of periodontitis with destructive changes in periodontal tissues in the frontal part of the mandible.

An in vitro comparison of three nucleus pulposus removal techniques for partial intervertebral disc replacement: An ultra-high resolution MRI study.

Nuclectomy, also known as nucleotomy, is a percutaneous surgical procedure performed to remove nucleus material from the center of the disc. Multiple techniques have been considered to perform a nuclectomy, however, the advantages and disadvantages of each are not well understood. This in vitro biomechanical investigation on human cadaveric specimens aimed to quantitatively compare three nuclectomy techniques performed using an automated shaver, rongeurs, and laser. Comparisons were made in terms of mass, volume and location of material removal, changes in disc height, and stiffness. Fifteen vertebra-disc-vertebra lumbar specimens were acquired from six donors (40 ± 13 years) and split into three groups. Before and after nucleotomy axial mechanical tests were performed and T2-weighted 9.4T MRIs were acquired for each specimen. When using the automated shaver and rongeurs similar volumes of disc material were removed (2.51 ± 1.10% and 2.76 ± 1.39% of the total disc volume, respectively), while considerably less material was removed using the laser (0.12 ± 0.07%). Nuclectomy using the automated shaver and rongeurs significantly reduced the toe-region stiffness (p = 0.036), while the reduction in the linear region stiffness was significant only for the rongeurs group (p = 0.011). Post-nuclectomy, 60% of the rongeurs group specimens showed changes in the endplate profile while 40% from the laser group showed subchondral marrow changes. From the MRIs, homogeneous cavities were seen in the center of the disc when using the automated shaver. When using rongeurs, material was removed non-homogeneously both from the nucleus and annulus regions. Laser ablation formed small and localized cavities suggesting that the technique is not suitable to remove large volumes of material unless it is developed and optimized for this application. The results demonstrate that both rongeurs and automated shavers can be used to remove large volumes of NP material but the reduced risk of collateral damage to surrounding tissues suggests that the automated shaver may be more suitable.

2-Mercaptoimidazole selectively etching and thiol-functionalized ZIF-8 metal–organic framework to serve as a multifaceted platform for radical scavenging and Au loading

Zeolite imidazole frameworks (ZIF-8) are a group of metal–organic frameworks (MOFs) that harbor application potential due to their unique high porosity and other physicochemical properties. However, the small cavities, unstable dispersion, and the lack of surface functional groups hinder the practical application of ZIF-8. In this study, we aimed to develop a ZIF-8-based multifaceted platform with hollow structure and abundant functional groups via a simple one-pot method. We synthesized the ZIF-8 with thiol functionalization (ZSH), while 2-mercaptoimidazole was served as both etching agent and functional counterpart. The hollow morphology and the thiol-groups modification were validated by scanning electron microscopy, transmission electron microscopy with energy-disperse X-ray mapping and X-ray photoelectron spectroscopy. The interparticle structure was estimated by Brunauer–Emmmett–Teller and ultraviolet–visible spectroscopy. The hollow architecture, colloidal stable, and thiol-abundant surface endow ZSHs exploiting the antioxidant and anti-inflammatory ability than pristine ZIF-8 toward a broad scale of morphological change with high functionalization degree. Moreover, ZSHs can specifically encapsulate gold nanoparticles in large quantities for further applications. Finally, ZSHs possess good biocompatibility in human cells and in vivo zebrafish model and could potentially protect human cells against oxidative stress. This concept valuably elucidated the new era for functionalized ZIF-8 to apply as the next generation of multifunctional biomaterials.