Trial of Early Minimally Invasive Removal of Intracerebral Hemorrhage.

BACKGROUND: Trials of surgical evacuation of supratentorial intracerebral hemorrhages have generally shown no functional benefit. Whether early minimally invasive surgical removal would result in better outcomes than medical management is not known. METHODS: In this multicenter, randomized trial involving patients with an acute intracerebral hemorrhage, we assessed surgical removal of the hematoma as compared with medical management. Patients who had a lobar or anterior basal ganglia hemorrhage with a hematoma volume of 30 to 80 ml were assigned, in a 1:1 ratio, within 24 hours after the time that they were last known to be well, to minimally invasive surgical removal of the hematoma plus guideline-based medical management (surgery group) or to guideline-based medical management alone (control group). The primary efficacy end point was the mean score on the utility-weighted modified Rankin scale (range, 0 to 1, with higher scores indicating better outcomes, according to patients' assessment) at 180 days, with a prespecified threshold for posterior probability of superiority of 0.975 or higher. The trial included rules for adaptation of enrollment criteria on the basis of hemorrhage location. A primary safety end point was death within 30 days after enrollment. RESULTS: A total of 300 patients were enrolled, of whom 30.7% had anterior basal ganglia hemorrhages and 69.3% had lobar hemorrhages. After 175 patients had been enrolled, an adaptation rule was triggered, and only persons with lobar hemorrhages were enrolled. The mean score on the utility-weighted modified Rankin scale at 180 days was 0.458 in the surgery group and 0.374 in the control group (difference, 0.084; 95% Bayesian credible interval, 0.005 to 0.163; posterior probability of superiority of surgery, 0.981). The mean between-group difference was 0.127 (95% Bayesian credible interval, 0.035 to 0.219) among patients with lobar hemorrhages and -0.013 (95% Bayesian credible interval, -0.147 to 0.116) among those with anterior basal ganglia hemorrhages. The percentage of patients who had died by 30 days was 9.3% in the surgery group and 18.0% in the control group. Five patients (3.3%) in the surgery group had postoperative rebleeding and neurologic deterioration. CONCLUSIONS: Among patients in whom surgery could be performed within 24 hours after an acute intracerebral hemorrhage, minimally invasive hematoma evacuation resulted in better functional outcomes at 180 days than those with guideline-based medical management. The effect of surgery appeared to be attributable to intervention for lobar hemorrhages. (Funded by Nico; ENRICH ClinicalTrials.gov number, NCT02880878.).

Physiological and molecular insights into the allelopathic effects on agroecosystems under changing environmental conditions.

Allelopathy is a natural phenomenon of competing and interfering with other plants or microbial growth by synthesizing and releasing the bioactive compounds of plant or microbial origin known as allelochemicals. This is a sub-discipline of chemical ecology concerned with the effects of bioactive compounds produced by plants or microorganisms on the growth, development and distribution of other plants and microorganisms in natural communities or agricultural systems. Allelochemicals have a direct or indirect harmful effect on one plant by others, especially on the development, survivability, growth, and reproduction of species through the production of chemical inhibitors released into the environment. Cultivation systems that take advantage of allelopathic plants' stimulatory/inhibitory effects on plant growth and development while avoiding allelopathic autotoxicity is critical for long-term agricultural development. Allelopathy is one element that defines plant relationships and is involved in weed management, crop protection, and microbial contact. Besides, the allelopathic phenomenon has also been reported in the forest ecosystem; however, its presence depends on the forest type and the surrounding environment. In the present article, major aspects addressed are (1) literature review on the impacts of allelopathy in agroecosystems and underpinning the research gaps, (2) chemical, physiological, and ecological mechanisms of allelopathy, (3) genetic manipulations, plant defense, economic benefits, fate, prospects and challenges of allelopathy. The literature search and consolidation efforts in this article shall pave the way for future research on the potential application of allelopathic interactions across various ecosystems.

Melanotic Neuroectodermal Tumor of Infancy of Jaws: A Case Report and Review of Literature.

Melanotic neuroectodermal tumor of infancy (MNTI) is an uncommon pigmented neural crest tumor primarily found in infants. We presented a case report of successful surgical management of MNTI in an 11-month-old female. A total of 178 articles discussing 249 cases of MNTI were identified through literature search. Literature review of 250 cases of MNTI including the current case report was conducted considering study parameters such as age and gender of the patient, location of the lesion, levels of vanillylmandelic acid, management options, and outcome after treatment. Statistical review of the data showed that MNTI predominantly affects the anterior maxilla in infants less than six months of age. Recurrence of the lesion shows a significant association with age of the individual and treatment method employed. This study reports a 2.4% mortality rate, 2% malignancy rate, and a recurrence rate of 15.2%, with recurrence times ranging from 15 days to 20 months. We advocate a minimum follow-up of four months to two years to monitor recurrence.

Nature-inspired polymer photocatalysts for green NADH regeneration and nitroarene transformation.

Photocatalysis has emerged as a promising approach for generating solar chemical and organic transformations under the solar light spectrum, employing polymer photocatalysts. In this study, our aim is to achieve the regeneration of NADH and fixation of nitroarene compounds, which hold significant importance in various fields such as pharmaceuticals, biology, and chemistry. The development of an in-situ nature-inspired artificial photosynthetic pathway represents a challenging task, as it involves harnessing solar energy for efficient solar chemical production and organic transformation. In this work, we have successfully synthesized a novel artificial photosynthetic polymer, named TFc photocatalyst, through the Friedel-Crafts alkylation reaction between triptycene (T) and a ferrocene motif (Fc). The TFC photocatalyst is a promising material with excellent optical properties, an appropriate band gap, and the ability to facilitate the regeneration of NADH and the fixation of nitroarene compounds through photocatalysis. These characteristics are necessary for several applications, including organic synthesis and environmental remediation. Our research provides a significant step forward in establishing a reliable pathway for the regeneration and fixation of solar chemicals and organic compounds under the solar light spectrum.

Engineered Artesunate-Naphthalimide Hybrid Dual Drug for Synergistic Multimodal Therapy against Experimental Murine Lymphoma.

Lymphoma can effectively be treated with a chemotherapy regimen that is associated with adverse side effects due to increasing drug resistance, so there is an emergent need for alternative small-molecule inhibitors to overcome the resistance that occurs in lymphoma management and overall increase the prognosis rate. A new series of substituted naphthalimide moieties conjugated via ester and amide linkages with artesunate were designed, synthesized, and characterized. In addition to the conjugates, to further achieve a theranostic molecule, FITC was incorporated via a multistep synthesis process. DNA binding studies of these selected derivatives by ultraviolet-visible (UV-vis), fluorescence spectroscopy, intercalating dye (EtBr, acridine orange)-DNA competitive assay, and minor groove binding dye Hoechst 33342-DNA competitive assay suggested that the synthesized novel molecules intercalated between the two strands of DNA due to its naphthalimide moiety and its counterpart artesunate binds with the minor groove of DNA. Napthalimide-artesunate conjugates inhibit the growth of lymphoma and induce apoptosis, including ready incorporation and reduction in cell viability. The remodeled drug has a significant tumoricidal effect against solid DL tumors developed in BALB/c mice in a dose-dependent manner. The novel drug appears to inhibit metastasis and increase the survival of the treated animals compared with untreated littermates.

Correction: Antiproliferative activity of Ni(II), Cu(II), and Zn(II) complexes of dithiocarbamate: synthesis, structural characterization, and thermal studies.

Correction for 'Antiproliferative activity of Ni(II), Cu(II), and Zn(II) complexes of dithiocarbamate: synthesis, structural characterization, and thermal studies' by Anupam Singh et al., Dalton Trans., 2024, 53, 1196-1208, https://doi.org/10.1039/D3DT03724J.

Evaluation of regulatory T-cells in cancer immunotherapy: therapeutic relevance of immune checkpoint inhibition.

The evolution of the complex immune system is equipped to defend against perilous intruders and concurrently negatively regulate the deleterious effect of immune-mediated inflammation caused by self and nonself antigens. Regulatory T-cells (Tregs) are specialized cells that minimize immune-mediated inflammation, but in malignancies, this feature has been exploited toward cancer progression by keeping the antitumor immune response in check. The modulation of Treg cell infiltration and their induction in the TME (tumor microenvironment) alongside associated inhibitory molecules, both soluble or membranes tethered in the TME, have proven clinically beneficial in boosting the tumoricidal activity of the immune system. Moreover, Treg-associated immune checkpoints pose a greater obstruction in cancer immunotherapy. Inhibiting or blocking active immune checkpoint signaling in combination with other therapies has proven clinically beneficial. This review summarizes the ontogeny of Treg cells and their migration, stability, and function in the TME. We also elucidate the Treg-associated checkpoint moieties that impede effective antitumor activity and harness these molecules for effective and targeted immunotherapy against cancer nuisance.

Antiproliferative activity of Fe(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes of dithiocarbamate: synthesis, structural characterization, and thermal studies.

Five new metal complexes of Fe(II) (1), Co(II) (2), Ni(II) (3), Cu(II) (4), and Zn(II) (5), derived from an N-cyclohexyl N-(3,4-dimethoxybenzyl) dithiocarbamate ligand, have been successfully synthesized and fully characterized by different analytical techniques i.e. elemental analyses, FT-IR, UV-Vis, 1H & 13C NMR, and HRMS. Furthermore, complexes 4 and 5 have been characterized by the SC-XRD technique. Complex 4 adopts a distorted square planar geometry around the Cu(II) center while complex 5 adopts a distorted tetrahedral geometry around the Zn(II) center. In addition, an eight-membered symmetric chair-like metallacycle ring containing two Zn(II) centers has also been found in complex 5. XRD data also show that complexes 4 and 5 are stabilized by various weak intermolecular hydrogen bonding interactions. The course of the thermal degradation of metal complexes 1-5 has been examined by TG-DTA data which revealed that metal sulphide formed as the final residue. Complexes 1-5 demonstrated concentration-dependent cytotoxicity and growth inhibition of DL tumor cells. Among the compounds, complexes 1, 4, and 5 showed significant cytotoxicity and induced a loss in the viability of DL cells. Therapy with complexes 1, 4, and 5 protects DL tumor-bearing animals from exacerbation of the disease, increases lifespan, and significantly improves the histopathological parameters of the vascularized organ, including preventing metastasis. Overall cytotoxicity assay results indicate that all complexes have remarkable cytotoxic potential in comparison with the free ligand.

Assessing the climate change impact on the habitat suitability of the range-restricted bird species (Catreus wallichii) in the Indian Himalayan ecosystem.

Climate change profoundly impacts ecosystems' function and composition, changing living organisms' habitats. The Indian Himalayan ecosystem (IHE) is particularly susceptible and vulnerable to the effects of climate change. However, our understanding of how climate change affects the habitats of range-restricted and vulnerable avifauna in the IHE still needs to be improved. Hence, we employed ensemble species distribution modelling to examine the potential habitat shift of the cheer pheasant (Catreus wallichii) under climate change scenarios (representative concentration pathways, RCPs) i.e. RCP 4.5, RCP 6.0 and RCP 8.5) by 2050 and 2070. The study revealed a noticeable expansion of climatically suitable habitats, indicating a shift towards higher altitudes that would become more favourable and suitable under future climates. The model predicted an area of very highly suitable habitat (1247.4 km2), followed by highly suitable (2747.9 km2), moderately suitable (4002.3 km2), low suitable (4952.2 km2) and rarely suitable (4236 km2) in the current scenario. The projection of larger areas was falling into the "no change", followed by the "high suitable" and "low suitable" classes, for both the years 2050 and 2070 across all the RCPs. Furthermore, the projections indicated a consistent trend of increasing suitability for the cheer pheasant at higher elevations and a decline at lower elevations across RCPs for 2050 and 2070. Moreover, the mean diurnal temperature range was identified as the crucial driving factor, followed by isothermally and precipitation, influencing the species' shift towards suitable habitats at higher altitudes. The study can aid policymakers in developing effective conservation strategies to protect Himalayan range-restricted bird species in the face of climate change.

Regulating adsorption performance of zeolites by pre-activation in electric fields.

While multiple external stimuli (e.g., temperature, light, pressure) have been reported to regulate gas adsorption, limited studies have been conducted on controlling molecular admission in nanopores through the application of electric fields (E-field). Here we show gas adsorption capacity and selectivity in zeolite molecular sieves can be regulated by an external E-field. Through E-field pre-activation during degassing, several zeolites exhibited enhanced CO2 adsorption and decreased CH4 and N2 adsorptions, improving the CO2/CH4 and CO2/N2 separation selectivity by at least 25%. The enhanced separation performance of the zeolites pre-activated by E-field was maintained in multiple adsorption/desorption cycles. Powder X-ray diffraction analysis and ab initio computational studies revealed that the cation relocation and framework expansion induced by the E-field accounted for the changes in gas adsorption capacities. These findings demonstrate a regulation approach to sharpen the molecular sieving capability by E-fields and open new avenues for carbon capture and molecular separations.

Protocol for Treatment of Oral Verrucous Carcinoma - A Systematic Review and Meta-Analysis.

Background: The objective of this study is to provide a structured protocol for the treatment of verrucous carcinoma (VC) based on size, bone invasion, recurrence and whether neck dissection is necessary or not. In addition, the study evaluates the probability of a wrong histopathological diagnosis. Data Sources: A search was conducted in the Cochrane Library, PubMed and Google from January 1962 to October 2022 by using MeSH terms and keywords. Studies reporting treatment modalities for VC and different histopathological diagnoses after excision of the lesion were selected except case reports and review articles. Study Eligibility Criteria: Thirteen articles were selected. Six hundred and thirty cases of VC were treated by surgery, surgery + neck dissection, radiotherapy, chemotherapy and combination therapy. Statistical analysis revealed surgical treatment as a preferred option. Despite being enlarged, the lymph node was negative for metastasis. So, in OVC cases neck dissection adds only unnecessary morbidity to patients. Participants and Interventions: Radiotherapy or chemotherapy can be used to downstage the disease. 23.3% of cases reported wrong histopathology diagnosis. Study Appraisal and Synthesis Methods: Patients treated for squamous cell carcinoma (SCC) will only experience unnecessary morbidity unless the correct diagnosis is made between VC and hybrid VC. Irrespective of size VC does not metastasise until there are no foci of SCC. Conclusions: Surgical excision of T1- and T2-sized lesions can be performed under local anaesthetic as a biopsy procedure. T3 or T4 lesion can be resected with a safe margin. If it comes as hybrid VC or VC with close margin (0.5 cm, <0.5 cm), neck dissection and further margin should be excised as a second procedure respectively.

Recent Advances in Chemotherapeutics for Leishmaniasis: Importance of the Cellular Biochemistry of the Parasite and Its Molecular Interaction with the Host.

Leishmaniasis, a category 1 neglected protozoan disease caused by a kinetoplastid pathogen called Leishmania, is transmitted through dipteran insect vectors (phlebotomine, sand flies) in three main clinical forms: fatal visceral leishmaniasis, self-healing cutaneous leishmaniasis, and mucocutaneous leishmaniasis. Generic pentavalent antimonials have long been the drug of choice against leishmaniasis; however, their success is plagued with limitations such as drug resistance and severe side effects, which makes them redundant as frontline therapy for endemic visceral leishmaniasis. Alternative therapeutic regimens based on amphotericin B, miltefosine, and paromomycin have also been approved. Due to the unavailability of human vaccines, first-line chemotherapies such as pentavalent antimonials, pentamidine, and amphotericin B are the only options to treat infected individuals. The higher toxicity, adverse effects, and perceived cost of these pharmaceutics, coupled with the emergence of parasite resistance and disease relapse, makes it urgent to identify new, rationalized drug targets for the improvement in disease management and palliative care for patients. This has become an emergent need and more relevant due to the lack of information on validated molecular resistance markers for the monitoring and surveillance of changes in drug sensitivity and resistance. The present study reviewed the recent advances in chemotherapeutic regimens by targeting novel drugs using several strategies including bioinformatics to gain new insight into leishmaniasis. Leishmania has unique enzymes and biochemical pathways that are distinct from those of its mammalian hosts. In light of the limited number of available antileishmanial drugs, the identification of novel drug targets and studying the molecular and cellular aspects of these drugs in the parasite and its host is critical to design specific inhibitors targeting and controlling the parasite. The biochemical characterization of unique Leishmania-specific enzymes can be used as tools to read through possible drug targets. In this review, we discuss relevant metabolic pathways and novel drugs that are unique, essential, and linked to the survival of the parasite based on bioinformatics and cellular and biochemical analyses.

The Function of Hydrotalcite as a Support Material in the Alcohol-Assisted Catalytic CO2 Hydrogenation Reaction.

The traditional CO2 hydrogenation reaction in gas phase always requires harsh reaction conditions to activate CO2 , resulting in huge energy consumption. However, with the assistance of 1-butanol solvent, catalytic CO2 hydrogenation can be proceeded at a mild condition of 170 °C and 30 bars. To further improve the catalytic performance of the widely studied Cu-ZnO-ZrO2 catalyst (CZZ), the catalysts were modified by incorporating hydrotalcite (HTC) as a support material. The addition of HTC significantly improved the copper dispersion and surface area of the catalyst. The performance of CZZ-HTC catalysts was investigated at varying weight percentages of HTC, and all showed higher space-time yield of methanol (STYMeOH ) compared to the commercial catalyst. Notably, CZZ-6HTC exhibited the highest methanol selectivity, further highlighting the beneficial role of HTC as a support material.

Biocompatible thermoresponsive N-isopropyl-N-(3-(isopropylamino)-3-oxopropyl)acrylamide-based random copolymer: synthesis and studies of its composition dependent properties and anticancer drug delivery efficiency.

A new acrylamide monomer, N-isopropyl-N-(3-(isopropylamino)-3-oxopropyl)acrylamide (M3i), consisting of both isopropyl and isopropylamidopropyl moieties, has been synthesized from isopropylamine and N-isopropylacrylamide via an aza-Michael addition reaction followed by amidation with acryloyl chloride. The homopolymer of M3i (polyM3i) and a series of random copolymers of M3i and poly(ethylene glycol)methyl ether acrylate (PEGA: CH2CHCO2(CH2CH2O)nMe, Mn = 480, n = 9 on average) with varying compositions have been synthesized via reversible addition-fragmentation chain transfer polymerization using 2-(dodecylthiocarbonothioylthio)-2-methylpropionic acid (DDMAT) as well as 1-phenylethyl phenyl dithioacetate (PEPD) as a RAFT agent. These polymers have been characterized by 1H NMR, FTIR, GPC, UV-Vis, fluorescence, TGDTA, DSC, DLS, and TEM techniques. A lower critical solution temperature (LCST) and glass transition temperature (Tg) for polyM3i prepared using DDMAT were observed at 17 and 133 °C, respectively, while for a polymer formed using PEPD, no LCST was observed until 0 °C and its observed Tg was found at 127.3 °C. The polymers are thermally stable up to 300 °C. Upon an increase in the M3i content in the copolymers, LCST decreases, Tg increases, and the apparent hydrodynamic diameter decreases. Moreover, the effects of concentration and the addition of urea and sodium chloride on the LCST of the copolymer with an LCST close to body temperature were studied. Owing to the incorporation of PEGA, a higher critical micellar concentration and larger TEM particle size of this copolymer were observed with respect to those of polyM3i. The usefulness of the micelles of the copolymers as nano-carriers for the drug doxorubicin was explored. The in vitro tumoricidal activity of the micelles of the doxorubicin-loaded copolymers was also assessed against Dalton's lymphoma cells.

γc cytokine-aided crosstalk between dendritic cells and natural killer cells together with doxorubicin induces a healer response in experimental lymphoma by downregulating FOXP3 and programmed cell death protein 1.

BACKGROUND AIMS: The stimulatory natural killer-dendritic cell axis in the tumor microenvironment could play a critical role in stimulating cytotoxic T cells and driving immune responses against cancer. METHODS: We established a novel treatment protocol by adroitly combining chemotherapy with doxorubicin and immunotherapy with dendritic cells and natural killer cells against a highly aggressive and malignant lymphoma called Dalton's lymphoma. RESULTS: Our data suggest that binary application of adoptive cell therapy and chemotherapy nearly cures (95%) early-stage experimental lymphoma. In the case of mid-stage cancer, the success rate was significantly lower but still impressive (75%). Our results demonstrated that the application of combination therapy in early-stage cancer significantly reduced the tumor volume and extended the lifespan of the experimental animal in addition to reinvigorating the immune system, including restoring the effector functions of dendritic cells and natural killer cells. The novel protocol limits the metastasis of tumor cells in vascularized organs and rearms the adaptive immune response mediated by dendritic cells and CD4+ and CD8+ T cells. CONCLUSIONS: Combination therapy in the early stage alters the cytokine profile, increases interferon-γ and tumor necrosis factor-α in the serum of treated animals and downregulates programmed cell death protein 1 expression in CD8+ T cells. Thus, cooperative and cognitive interactions between dendritic cells and natural killer cells in addition to therapy with doxorubicin promote the immune response and tumoricidal activities against lymphoma.

Nanoscale Diamond-Based Formulation as an Immunomodulator and Potential Therapeutic for Lymphoma.

Integrative medicine practices, such as Ayurveda, are popular in India and many South Asian countries, yet basic research to investigate the concepts, procedures, and medical benefits of ayurvedic products has received little attention and is not fully understood. Here, we report a functional nanodiamond-based traditional Ayurvedic herbomineral formulation, Heerak Bhasma (Ayu_ND), for the treatment of solid tumors called Dalton's lymphoma generated in CD1 mice. Ayu_ND-mediated immunostimulation significantly reduces tumor cell proliferation and induces apoptosis aided by the active participation of dendritic cells. Immunomodulatory Ayu_ND treatment is highly immunostimulatory and drives dendritic cells to produce TNF-α. Treatment with Ayu_ND significantly reduces the tumor volume, inhibits metastasis in distant vascularized organs, and increases the life span of tumor-bearing animals compared with untreated littermates. These events were associated with elevated serum levels of the protective cytokines IFN-γ and TNF-α and downregulated the disease, exacerbating TGF-ß. Ayu_ND-mediated therapeutic success was also accompanied by the depletion of regulatory T cells and enhanced vaccine-induced T-cell immunity, guided by the restoration of the memory CD8+ T-cell pool and prevention of PD-1-mediated T cell exhaustion. The results provide a basis for further evaluation of ayurvedic formulations and drug efficacy in treating cancers.

Pseudotumor Cerebri Syndrome (PTCS), Clinico-Radiological Profile: A Prospective Study.

Objectives: The aim of the study was to classify patients of Pseudotumor Cerebri Syndrome (PTCS) on the basis of newer classification along with its clinico-radiological correlations. Patients and Methods: A prospective study was conducted at a tertiary care teaching hospital. A total of 25 consecutive patients who fulfilled the new diagnostic criteria for PTCS were enrolled after taking informed written consent. A thorough clinical history, neurological examination and neuroimaging was carried out. Patients were classified into Primary and Secondary PTCS followed by Definite, Probable and Suggested as per new nomenclature. Results: Out of 25 patients, there were 9 patients in the primary PTCS group and 16 in the secondary PTCS group. Mean duration of symptoms was 40.84 ± 45.68 days. Primary PTCS group patients were significantly overweight and had higher BMI as compared to the secondary group with significant number of patients reporting recent rapid weight gain. The CSF pressure and protein were non-significantly higher in the primary PTCS group. We could classify 17 (68%) patients in our study as definite PTCS, 7 (28%) as probable PTCS and suggested PTCS in one patient. In secondary PTCS group there were 16 (64%) patients. APLA positivity was found to be the most common etiology for secondary PTCS with statistical significance (P = 0.025). Conclusions: Early recognition along with appropriate classification and prompt treatment can prevent vision loss in PTCS. Apart from obesity, recent weight gain is also closely related with primary PTCS.

Electrical Regulation of CO2 Adsorption in the Metal-Organic Framework MIL-53.

Active regulation of pore accessibility in microporous materials by external stimuli has aroused great attention in recent years. Here, we show the first experimental proof that guest adsorption in a dielectric microporous material can be regulated by a moderate external E-field below the gas breakdown voltage. CO2 adsorption capacity in MIL-53 (Al) was significantly reduced, whereas that of NH2-MIL-53 (Al) changed insignificantly under a direct current E-field gradient of 286 V/mm. Ab initio DFT calculations revealed that the E-field decreased the charge transfer between the CO2 molecule and the adsorption site in the MIL-53 framework, which resulted in reduced binding energy and consequently lowered CO2 adsorption capacity. This effect was only observed in the narrow pore state MIL-53 (Al) but not in its large pore configuration. Our results demonstrate the feasibility of regulating the adsorption of gas molecules in microporous materials using moderate E-fields.

Gating effect for gas adsorption in microporous materials-mechanisms and applications.

In the past two decades, various microporous materials have been developed as useful adsorbents for gas adsorption for a wide range of industries. Considerable efforts have been made to regulate the pore accessibility in microporous materials for the manipulation of guest molecules' admission and release. It has long been known that some microporous adsorbents suddenly become highly accessible to guest molecules at specific conditions, e.g., above a threshold pressure or temperature. This anomalous adsorption behavior results from a gating effect, where a structural variation of the adsorbent leads to an abrupt change in the gas admission. This review summarizes the mechanisms of the gating effect, which can be a result of the deformation of the framework (e.g., expansion, contraction, reorientation, and sliding of the unit cells), the vibration of the pore-keeping groups (e.g., rotation, swing, and collapse of organic linkers), and the oscillation of the pore-keeping ions (e.g. cesium, potassium, etc.). These structural variations are induced either by the host-guest interaction or by an external stimulus, such as temperature or light, and account for the gating effect at a threshold value of the stimulus. Emphasis is given to the temperature-regulated gating effect, where the critical admission temperature is dictated by the combined effect of the gate opening and thermodynamic factors and plays a key role in regulating guest admission. Molecular simulations can improve our understanding of the gate opening/closing transitions at the atomic scale and enable the construction of quantitative models to describe the gated adsorption behaviour at the macroscale level. The gating effect in porous materials has been widely applied in highly selective gas separation and offers great potential for gas storage and sensing.

Nitrogen Rejection from Methane via a "Trapdoor" K-ZSM-25 Zeolite.

Nitrogen (N2) rejection from methane (CH4) is the most challenging step in natural gas processing because of the close similarity of their physical-chemical properties. For decades, efforts to find a functioning material that can selectively discriminate N2 had little outcome. Here, we report a molecular trapdoor zeolite K-ZSM-25 that has the largest unit cell among all zeolites, with the ability to capture N2 in favor of CH4 with a selectivity as high as 34. This zeolite was found to show a temperature-regulated gas adsorption wherein gas molecules' accessibility to the internal pores of the crystal is determined by the effect of the gas-cation interaction on the thermal oscillation of the "door-keeping" cation. N2 and CH4 molecules were differentiated by different admission-trigger temperatures. A mild working temperature range of 240-300 K was determined wherein N2 gas molecules were able to access the internal pores of K-ZSM-25 while CH4 was rejected. As confirmed by experimental, molecular dynamic, and ab initio density functional theory studies, the outstanding N2/CH4 selectivity is achieved within a specific temperature range where the thermal oscillation of door-blocking K+ provides enough space only for the relatively smaller molecule (N2) to diffuse into and through the zeolite supercages. Such temperature-regulated adsorption of the K-ZSM-25 trapdoor zeolite opens up a new approach for rejecting N2 from CH4 in the gas industry without deploying energy-intensive cryogenic distillation around 100 K.