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The unique characteristic of superatoms to show chemical properties like those of individual atoms opens a new avenue towards replacing noble metals as catalysts. Given the similar electronic structures of the ZrO superatom and the Pd atom, the CO oxidation mechanisms catalysed by (ZrO) n (n = 1-4) clusters were investigated in detail to evaluate their catalytic performance. Our results reveal that a single ZrO superatom exhibits superior catalytic ability in CO oxidation than both larger (ZrO) n (n = 2-4) clusters and a Pd atom, indicating the promising potential of ZrO as a "single-superatom catalyst". Moreover, the mechanism of CO oxidation catalysed by ZrO+/- suggests that depositing a ZrO superatom onto the electron-rich substrates is a better choice for its practical application in catalysis. Accordingly, a graphene nanosheet (coronene) was chosen as a representative substrate for ZrO and Pd to assess their catalytic performances in CO oxidation. Acting as an "electron sponge", this carbon substrate can both donate and accept charges in different reaction steps, enabling the supported ZrO to achieve enhanced catalytic performance in this process with a low energy barrier of 19.63 kcal/mol. This paper presents a new realization on the catalytic performance of Pd-like superatom in CO oxidation, which could increase the interests in exploring noble metal-like superatoms as efficient catalysts for various reactions.

The discovery of tungsten carbide (WC) as an analog of the noble metal Pt atom is of great significance toward designing novel highly-active catalysts from the viewpoint of the superatom concept. The potential of such a superatom to serve as building blocks of replacement catalysts for Pt has been evaluated in this work. The electronic properties, adsorption behaviors, and catalytic mechanisms towards the CO oxidation of (WC)

An environmentally friendly and efficient protocol for the synthesis of benzimidazoles by mortar–pestle grinding technique in the presence of acetic acid as a catalyst is reported. This mechanochemical method proceeded with the condensation of aldehyde and o-phenylenediamine followed by cyclization reaction, leading to the formation of the corresponding benzimidazoles in yields up to 97%. This protocol could also be applied for the synthesis of benzothiazoles and benzoxazoles.

The potential application of an experimentally synthesized superatom Ti@Si

Objective. Interleukin 33 (IL-33) is a key cytokine involved in inflammation and oxidative stress. The significance of serum IL-33 levels on the prognosis of patients with intracerebral hemorrhage (ICH) has not been well studied. The purpose of this study is to determine whether there is a relationship between the serum IL-33 level and the prognosis of patients with ICH upon admission. Methods. A total of 402 patients with confirmed ICH were included in this study. Their demographic data, medical history, laboratory data, imaging data, and clinical scores on admission were collected. At the same time, enzyme-linked immunoassay (ELISA) was used to detect the serum IL-33 levels of patients. The prognosis of patients was evaluated by mRS scale after 3 months, and mRS > 2 was defined as poor prognosis. Results. Among 402 patients with ICH, the number of patients with good prognosis and poor prognosis after 3 months was 148 and 254, respectively. Compared with the ICH group with poor prognosis, the ICH group with good prognosis had lower baseline NHISS scores ( p = 0.039 ) and hematoma volume ( p = 0.025 ) and higher GCS scores ( p < 0.001 ) and serum IL-33 levels ( p < 0.001 ). The results of linear correlation analysis showed that serum IL-33 levels were significantly negatively correlated with baseline NHISS scores ( r = − 0.224 , p = 0.033 ) and hematoma volume ( r = − 0.253 , p = 0.046 ) but were significantly positively correlated with baseline GCS scores ( r = 0.296 , p = 0.020 ). The receiver operating characteristic curve (ROC) analysis showed that the sensitivity and specificity of serum IL-33 level in evaluating the prognosis of ICH were 72.1% and 74.3%, respectively. A cut-off value of serum IL-33 level < 109.3 pg/mL may indicate a poor prognosis for ICH. Conclusions. Serum IL-33 level on admission may be a prognostic indicator of ICH, and its underlying mechanism needs further study.

Ever since the concept of superatoms was brought forward in the 1990s, various specific types of clusters have been proposed to mimic atomic properties and enrich the "three-dimensional periodic table". In this work, a Zintl cluster, namely, Ge9Be, has been certified eligible to join the superatom family, owing to its surprising similarity to chalcogen elements. Having 38 valence electrons, Ge9Be has an intrinsic desire to gain two additional electrons to achieve electronic shell closure, in which its quasi-chalcogen identity roots. Like oxygen-group elements, Ge9Be has the potential to form stable ionic compounds with lithium, beryllium, calcium, and superalkaline-earth atom FLi3. On the other hand, the combination of Ge9Be and the multiple valence superatom Al7- results in covalent compounds resembling carbon oxides. Close parallels have also been found between (Ge9Be)2-based compounds and common peroxides, further evidencing the superatom characteristics of Ge9Be. This finding puts forward an almost perfect superatom counterpart of group VIA elements and opens the door to characteristics-oriented design and synthesis of stable superatom motifs by utilizing solid Zintl clusters.

The development of protocols for synthesizing quinazolinones using biocompatible catalysts in aqueous medium will help to resolve the difficulties of using green and sustainable chemistry for their synthesis. Herein, using I2 in coordination with electrochemical synthesis induced a C–H oxidation reaction which is reported when using water as the environmentally friendly solvent to access a broad range of quinazolinones at room temperature. The reaction mechanism strongly showed that I2 cooperates electrochemically promoted the oxidation of alcohols, then effectively cyclizing amides to various quinazolinones.

An electrochemically induced C(sp3)–H amination of 2-aminobenzamides with ketones using TBAI as a catalyst was developed, and provided 2-benzoylquinazolin-4(3H)-ones under metal-free conditions. The reaction proceeded using the relatively low-toxicity methanol as the solvent, employed molecular oxygen as the ideal green oxidant in a simple undivided cell, and exhibited high atom economy. The mechanism of this C(sp3)–H amination strategy was concluded to involve generation of an acetophenone radical, and its easy further oxidation to form 2-oxo-2-phenylacetaldehyde.

A K2S2O8-promoted oxidative tandem cyclization of primary alcohols with 2-aminobenzamides to synthesize quinazolinones was successfully achieved under undivided electrolytic conditions without a transition metal and base. The key feature of this protocol is the utilization of K2S2O8 as an inexpensive and easy-to-handle radical surrogate that can effectively promote the reaction via a simple procedure, leading to the formation of nitrogen heterocycles via direct oxidative cyclization at room temperature in a one-pot procedure under constant current. Owing to the use of continuous-flow electrochemical setups, this green, mild and practical electrosynthesis features high efficiency and excellent functional group tolerance and is easy to scale up.

The adsorption of 5-fluorouracil on B40 and its derivatives has been theoretically studied to provide some implications for the potential application of B40 in drug delivery.

Converting earth-abundant nitrogen (N2) gas into ammonia (NH3) under mild conditions is one of the most important issues and a long-standing challenge in chemistry. Herein, a new superatom Ca3B was theoretically designed and characterized to reveal its catalytic performance in converting N2 into NH3 by means of density functional theory (DFT) computations. The alkali-metal-like identity of this cluster is verified by its lower vertical ionization energy (VIE, 4.29 eV) than that of potassium (4.34 eV), while its high stability was guaranteed by the large HOMO–LUMO gap and binding energy per atom (Eb). More importantly, this well-designed superatom possesses unique geometric and electronic features, which can fully activate N2via a “double-electron transfer” mechanism, and then convert the activated N2 into NH3 through a distal reaction pathway with a small energy barrier of 0.71 eV. It is optimistically hoped that this work could intrigue more endeavors to design specific superatoms as excellent catalysts for the chemical adsorption and reduction of N2 to NH3.

The thinnest beryllium nanowires with high strength and uniformity are theoretically constructed of connected Be6 octahedron units. Based on this, Ca- and Mg-doped beryllium nanowires are successfully constructed and researched. They are unusual all-metal charge transfer salts Ca2+(Be6)n4-Mg2+ (n = 1-7), and they surprisingly display considerable second-order nonlinear optical (NLO) responses (β0e = 1.05 × 104-1.12 × 105 au). This is because the effect of doping Ca and Mg atoms brings great increase in β0e. In addition, more notably, the effect of the nanowire length on β0e revealed that the β0e value gradually and rapidly increases with the increase in the number of Be6 octahedron units (n). Thus, these doped beryllium nanowires are a new class of NLO nanowires. Fortunately, these NLO nanowires possess working wavebands in the infrared (IR, >2800 nm) and ultraviolet (UV

Developing efficient catalysts for the conversion of CO2 into fuels and value-added chemicals is of great significance to relieve the growing energy crisis and global warming. With the assistance of DFT calculations, it was found that, different from Al12 X (X=Be, Al, and C), the alkali-metal-like superatom Al12 P prefers to combine with CO2 via a bidentate double oxygen coordination, yielding a stable Al12 P(η2 -O2 C) complex containing an activated radical anion of CO2 (i.e., CO2 .- ). Thereby, this compound could not only participate in the subsequent cycloaddition reaction with propylene oxide but also initiate the radical reaction with hydrogen gas to form high-value chemicals, revealing that Al12 P can play an important role in catalyzing these conversion reactions. Considering that Al12 P has been produced in laboratory and is capable of absorbing visible light to drive the activation and transformation of CO2 , it is anticipated that this work could guide the discovery of additional superatom catalysts for CO2 transformation and open up a new research field of superatom catalysis.

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) induced a worldwide pandemic. The main clinical manifestations of COVID-19 patients have been fever, cough, dyspnea, and other respiratory symptoms. However, some patients’ initial symptoms have been nausea, vomiting, diarrhea and other gastrointestinal symptoms, and SARS-CoV-2 RNA could be found in their stool samples. Studies have shown that the gastrointestinal tract highly-expressed angiotensin-converting enzyme 2 is used by SARS-CoV-2 to enter cells. Therefore, exploring the damage caused by SARS-CoV-2 to the gastrointestinal tract and whether it could replicate in the gastrointestinal tract and transmit through fecal-oral route has significance for the diagnosis, treatment and prevention of COVID-19. We combined the current clinical data about COVID-19 patients with gastrointestinal symptoms as well as its pathogenic mechanism and prevention methods herein to review the relationship between the disease and gastrointestinal symptoms.

Theoretically, the two aldehydes of terephthalaldehyde (TPA) are equivalent, so the single or double Schiff base from TPA and d-glucosamine (Glc) may be formed at the same time. However, it is preferred to produce separately a single Schiff base (L1 ) or double Schiff base (L2 ) for different synthesis systems of anhydrous methanol or water-methanol. We calculated the Δr G of the formation of compounds L1 and L2 by density functional theory (DFT). In an anhydrous methanol system, the Δr G values of L1 and L2 are both below zero and L2 is lower, suggesting the spontaneous formation of the two Schiff bases. Though adjusting the molar ratio of Glc to TPA, L1 and L 2 both were separately formed in anhydrous methanol. However, in the water-methanol system, L2 was absent, which is most likely due to higher Δr G (4.95 eV) and better water solubility. The results also exhibits that the positive charge of C in -CHO for TPA is smaller in a mixed solvent than that in methanol, which confirms that the nucleophilic reaction of the Schiff base is more difficult in a mixed solvent. Therefore, we could realize to control the synthesis of a pure single or double Schiff base from Glc and TPA by adjusting the molar ratio and solvent. The as-prepared two kinds of Schiff bases have strong optical properties, high bacteriostatic activity, and can be used as fluorescent probes for tumor cell imaging.

The interaction between quasi-chalcogen superatom Al12Be and DNA nucleobases/base pairs has been explored by searching for the most stable Al12Be–X (X = DNA bases and base pairs) complexes. Our results reveal that Al12Be prefers to combine with guanine by two Al–O and Al–N bonds rather than the other DNA bases, no matter in free state or base pair. The formed Al–N and Al–O bonds between Al12Be and DNA bases proved to be strong polar covalent bonds by the Wiberg bond index, nature bond orbitals, atoms in molecules theory, localized molecular orbitals, and electron localization functions analyses. More importantly, it is found that the formed global minimum of Al12Be–G has the ability to activate an oxygen molecule into a peroxide dianion 1O22–, which can further catalyze the CO oxidation via the Eley–Rideal mechanism with a small energy barrier of 7.78 kcal/mol. We hope that this study could not only provide an in-depth understanding on the intermolecular interaction between metallic superatoms and DNA at the molecular level but also attract more interest in designing and synthesizing superatom-based heterogeneous catalysts with DNA/nucleobases as basic building blocks.

In this study, to examine the possibility of using cage-like complexants to design nonmetallic superalkalis, a series of X@36adz (X = H, B, C, N, O, F, and Si) complexes have been constructed and investigated by embedding nonmetallic atoms into the 36adamanzane (36adz) complexant. Although X atoms possess very high ionization energies, these resulting X@36adz complexes possess low adiabatic ionization energies (AIEs) of 0.78–5.28 eV. In particular, the adiabatic ionization energies (AIEs) of X@36adz (X = H, B, C, N, and Si) are even lower than the ionization energy (3.89 eV) of Cs atoms, and thus, can be classified as novel nonmetallic superalkalis. Moreover, due to the existence of diffuse excess electrons in B@36adz, this complex not only possesses pretty low AIE of 2.16 eV but also exhibits a remarkably large first hyperpolarizability (β0) of 1.35 × 106 au, indicating that it can also be considered as a new kind of nonlinear optical molecule. As a result, this study provides an effective approach to achieve new metal-free species with an excellent reducing capability by utilizing the cage-like organic complexants as building blocks.

Based on density functional theory, the adsorption behavior of 5-fluorouracil (5-Fu) on B

Converting earth-abundant nitrogen (N

The potential of the superalkali cation Li3+ for capturing N2 and its behavior in gaseous nitrogen have been theoretically studied at the MP2/6-311+G(d) level. The evolution of structures and stability of the Li3+(N2)n (n = 1-7) complexes shows that the N2 molecules tend to bind to different vertices of the Li3+ core, and that Li3+ might have the capacity to capture up to twelve nitrogen molecules in the first coordination shell. Based on natural population and molecular orbital analyses, Li3+ keeps its superatom identity in the lowest-lying Li3+(N2)n (n = 1-4) complexes. The change in the Gibbs free energies of possible fragmentation channels also indicates the thermodynamic stability of Li3+ in the (N2)n clusters when n ≤ 4. Different from the case of Li3+(H2O)n, where the electrostatic interaction is dominant, the electrostatic and polarization components are found to make nearly equal contributions to Li3+(N2)n complex formation. In addition, it can be concluded that the superalkali cation Li3+ surpasses heavy alkali metal cations in capturing N2 molecules, since it has a larger binding energy with N2 than Na+ and K+ ions.

For the challenge of stabilizing a fullerene-like borospherene, a perfect fullerene-like borospherene B20 with Ih symmetry is stabilized theoretically for the first time by selected 12 η5 (pentahapto)-Mg atoms capped on the 12 B5 pentagons, forming an exohedral metalloborospherene Ih Mg12&B20 molecule. Owing to the pull–push electron transfer relay, the molecule is converted to a spherical electride molecule (Mg2+)12&B2018− + 6e− with multiexcess electrons and high-valent B2018− polyanion with a full-shell electronic configuration, performing the stabilization of the fullerene-like B20 cage. Furthermore, we embed the metal M atom in the B20 cage, forming new endohedral electride molecules (Mg2+)12&(Mn+@B2018−) + (6 + n)e− (M = Li, n = 1 and Mg, n = 2). The embedded atom M increases the excess electron number. Notably, these electride molecules possess two different types of superatomic characteristics, exhibiting the behavior of an electron reservoir. Moreover, a compound (Mg12&B20)2O is designed and obtained, so Mg12&B20 might serve as a nano-building block. In addition, the Mg12&B20 and Mg12&(Mg@B20) electride molecules are efficient external electric field-manipulated nonlinear optical (NLO) switches with high sensitivity and reversibility. The embedding metal atom in the B20 cage can also serve as a new strategy to manipulate NLO switching.

An intriguing class of excess electron compounds with unique electronic structures was obtained on the basis of a facially polarized molecule, namely, all-cis-1,2,3,4,5,6-hexafluorocyclohexane (1). By doping two different faces of this Janus molecule with an alkaline earth atom and an alkali-metal atom, a series of M-1-M′ (M = Be, Mg, and Ca; M′ = Li, Na, and K) compounds were first constructed. The calculated results show that unlike Be and Mg, one 4s electron of Ca in Ca+-1-M′− (M′ = Li, Na, and K) can be transferred to the upper alkali metal atom, thus forming an alkali metal anion, while the remaining 4s electron of Ca is pushed away from Ca+, yielding localized electrons around it by the instinctive facial polarization of 1 or with the assistance of oriented external electric fields (OEEFs). Interestingly, these novel compounds exhibit extremely large first hyperpolarizabilities (β0) in the range of 9.94 × 105–1.81 × 106 a.u. and high stability. Thus, this work can provide first members simultaneously containing typical alkalide features and electride-like characteristics to further enrich the family of excess electron compounds and offer novel candidates for NLO materials with high performance.

A systematic analysis of electronic and nonlinear optical properties of a novel class of (super)alkali-doped complexes M/M3O@g-C3N4 (M Li, Na, K) is presented. These compounds exhibit considerable stability with large interaction energies, and M3O@g-C3N4 has higher stability than the corresponding M@g-C3N4. It is found that doping the (super)alkali can significantly narrow the wide energy gap of the pure g-C3N4 in the range of 2.04–2.84 eV, and these doped g-C3N4 show enhanced visible-light absorption. Due to the large charge transfer from (super)alkali to g-C3N4 moiety, these doped compounds exhibited significantly large first hyperpolarizabilities up to 2165–63761 au. The ratio between the vibrational and electronic contribution on hyperpolarizability indicates that the vibrational contributions play an important role in determining the static hyperpolarizabilities of certain systems. Therefore, (super)alkali-doped g-C3N4 are expected to be potential candidates for visible-light catalysis and high-performance nonlinear optical materials. We expect this work could provide a new idea for designing functional materials using superalkali clusters.

Numerous isomeric equilibrium structures have been identified for the Al10–xBex (x = 1–9) nanoalloy clusters by using the stochastic search procedure in combination with density functional theory calculations. The relative stability and various electronic properties of the lowest-energy Al10–xBex (x = 0–10) clusters have been systematically studied by using the B3LYP and CCSD(T) methods with the aug-cc-pVDZ basis set. The evolution of the binding energies, the second difference in energy, HOMO–LUMO gaps, vertical detachment energies, vertical ionization potentials, vertical electron affinities, and hardness with the increasing number of Be atoms in the most stable Al10–xBex (x = 0–10) clusters demonstrates that the global minimum of Al8Be2 cluster possesses a special stability. Thus, the electronic structure of the lowest-energy Al8Be2 cluster has been also detected in detail. In addition, it is found that the polarizabilities gradually decrease with increasing number of Be atoms, and the charges always transfer from Al to Be atoms in these nanoalloy clusters. We hope this work could provide helpful insight into the composition-dependent electronic properties of Be Al alloy at the nanoscale, serving as powerful guidelines for future experimental research.

Currently, case studies or clinical trials in different patient populations remain the main resource underlying the understanding of disorder of consciousness (DoC). This provides a low efficacy for the derivation of data and the implementation of associated controlled experimental designs. Preclinical models provide precise controls, reduced variability, rich data output and limited ethical complexity. Nonhuman primates are suitable model animals for disorders of consciousness due to their brain structure being very similar to that of humans. Behavioral tests remain the primary standard for assessing the consciousness status of humans. However, there is currently no behavioral assessment scale available for evaluation of the state of consciousness disorder in nonhuman primates. This presents a significant challenge for the establishment of different models of consciousness disorder. Therefore, there is considerable motivation to focus on the development of a proper tool for assessment of the state of consciousness associated with nonhuman primate models that are based on clinically common consciousness assessment scales.It is assumed that the Delphi and level analysis methods based on clinical consciousness disorder assessment scales may provide an effective way to select and include assessment indexes for levels of consciousness in nonhuman primates.8 first-level indicators with 41 second-level indexes were selected preliminary as a pool of evaluation entries of state of consciousness of nonhuman primates.It may be practicable to extract appropriate indicators for non-human primates from the clinical consciousness disorder assessment scales. Besides, a combination of Delphi method, behavioral analysis, electroencephalography, neuroimaging (such as positron emission tomography-computed tomography) and functional magnetic resonance imaging is necessary to test the reliability and validity of the novel scale reported here.

Exosomes are promising biomarkers for cancer screening, but the development of a robust approach that can sensitively and accurately detect exosomes remains challenging. In the present study, an aptasensor based on the multifunctional signal probe 10-benzyl-2-amino-acridone (BAA) was developed for the colorimetric and photoelectrochemical detection and quantitation of exosomes. Exosomes are captured by cholesterol DNA anchor-modified magnetic beads (MBs) through hydrophobic interactions. This capture process can be monitored under a confocal fluorescence microscope using BAA as the fluorescent signal probe. The aptamer modified copper oxide nanoparticles (CuO NPs) then bind to mucin 1 (MUC1) on the surface of the exosomes to form a sandwich structure (MBs-Exo-CuO NPs). Finally, the MBs-Exo-CuO NPs are dissolved in nitric acid to generate Cu2+, which inhibits the visible-light-induced oxidase mimic activity and photoelectrochemical activity of BAA simultaneously. The changes in absorbance and photocurrent intensities are directly proportional to the concentration of exosomes. In this dual-modal aptasensor, the colorimetric assay can achieve rapid screening and identification, which is especially useful for point-of-care testing. The UV–vis absorbance and photocurrent assays then provide quantitative information, with a limit of detection of 1.09 × 103 particles μL−1 and 1.38 × 103 particles μL−1, respectively. The proposed aptasensor thus performs dual-modal detection and quantitation of exosomes. This aptasensor provides a much-needed toolset for exploring the biological roles of exosomes in specific diseases, particularly in the clinical setting.

Objective. Neuropeptide Y (NPY), a 36-amino acid neuromodulator, is mainly secreted by neurons in the central and peripheral nervous systems, which participate in the regulation of a series of physiological processes. However, there are few studies on its correlation with intracranial hemorrhage (ICH). The purpose of this study is to determine whether the serum NPY level is related to the prognosis of ICH. Methods. 364 patients diagnosed with ICH were included in the current study. The demographics, anthropometrics, medical history, clinical severity, and laboratory data are collected. Enzyme-linked immunoassay (ELISA) was used to detect the serum NPY level of each patient upon admission. Three months after the occurrence of ICH, we used the modified Rankin scale (mRS) to evaluate the prognosis of patients, and mRS > 2 was defined as a poor prognosis. Results. A total of 364 patients with ICH were included in the study, including 140 patients with a good prognosis and 224 patients with a poor prognosis. Compared with patients with a poor prognosis, ICH patients with a good prognosis have a lower baseline National Institutes of Health Stroke Scale (NIHSS) score ( p = 0.036 ) and smaller hematoma volume ( p = 0.039 ). The results of ELISA showed that compared with patients with a poor prognosis, ICH patients with a good prognosis had lower serum NPY levels ( 19.4 ± 3.7 vs. 27.6 ± 3.3 ng/ml, p < 0.001 ). Linear correlation analysis showed that the serum NPY level of ICH patients was significantly positively correlated with the baseline NIHSS score ( r = 0.413 , p = 0.041 ) and hematoma volume ( r = 0.308 , p = 0.026 ). Receiver operating characteristic (ROC) curve analysis showed that the sensitivity of the serum NPY level to predict the prognosis of ICH was 70.9%, the specificity was 72.6%, and the cut-off value was 24.2 ng/ml. Conclusions. The serum NPY level may be used as a predictor of ICH prognosis.

The potential of the superalkali cation Li3+ for capturing N2 and its behavior in gaseous nitrogen have been theoretically studied at the MP2/6-311+G(d) level. The evolution of structures and stability of the Li3+(N2)n (n = 1-7) complexes shows that the N2 molecules tend to bind to different vertices of the Li3+ core, and that Li3+ might have the capacity to capture up to twelve nitrogen molecules in the first coordination shell. Based on natural population and molecular orbital analyses, Li3+ keeps its superatom identity in the lowest-lying Li3+(N2)n (n = 1-4) complexes. The change in the Gibbs free energies of possible fragmentation channels also indicates the thermodynamic stability of Li3+ in the (N2)n clusters when n ≤ 4. Different from the case of Li3+(H2O)n, where the electrostatic interaction is dominant, the electrostatic and polarization components are found to make nearly equal contributions to Li3+(N2)n complex formation. In addition, it can be concluded that the superalkali cation Li3+ surpasses heavy alkali metal cations in capturing N2 molecules, since it has a larger binding energy with N2 than Na+ and K+ ions.

Electrochemotherapy is an effective strategy for the treatment of solid tumors by exposing tumor cells to electric fields to enhance the bioactivity of non-permeable or low permeable anticancer drugs, such as cisplatin. To understand the improved efficiency of cisplatin in electrochemotherapy, the effects of oriented external electric fields (OEEFs) on the geometric structures and relevant electronic properties of cisplatin have been systemically investigated by density functional theory (DFT) computations in this work. Our results reveal that the presence of positive OEEFs on cisplatin can not only weaken its Pt-Cl bonds, but also enhance the intramolecular charge transfer in it, which effectively accelerates the critical hydrolysis step involved in the mechanism of its biological activity. Moreover, the positive OEEFs can facilitate the attack of the singly aquated cis-[Pt(NH3)2(H2O)Cl]+ on DNA, and enlarge the dipole moments and water solubility of cisplatin and its aquated product. Consequently, this work provides a deeper insight into the higher efficacy of electrochemotherapy than traditional chemotherapy from a molecular point of view.

Exosomal microRNAs (miRNAs) are vital biomarkers for early diagnosis and prognosis monitoring of cancer. Yet, convenient and controllable detection of exosomal miRNA still remains challenges because of lacking of adequately simple and robust assay platforms. In this paper, it is first time to study the visible-light-induced oxidase mimic activity of 10-methyl-2-amino-acridone (MAA) being able to be switched by Cu2+ and DNA. Based on this phenomenon, a series of visual molecular logic gates are constructed, and a colorimetric strategy has been developed to achieve exosomal microRNA-21 (miR-21) detection with a signal amplification approach. The visible-light-induced oxidase mimic activity of MAA can be inhibited by Cu2+. In presence of target, a large amount of capture probes partly complementary with miR-21 are hydrolyzed with the assist of duplex-strand specific nuclease (DSN), releasing guanine-rich oligodeoxynucleotides that can chelate Cu2+, resulting in catalytic activity of MAA being recovered under irradiation. This strategy allows the detection of miR-21 with a light modulating temporal controllable manner, and the linear range is from 50 fM to 3000 fM with the limit of detection (LOD) being 44.76 fM. More importantly, the proposed method can achieve quantitative measurement of exosomal miR-21 that is derived from three-dimensional multicellular tumor spheroids with different size, which is able to monitor the growth of tumor spheroids. This work is potential to provide a feasible tool for application in exosomal miRNAs-based cancer diagnosis. Ultimately, MAA is expected to be a signal probe in biomedical field by virtue of its fascinating visible-light-induced oxidase mimic activity.

Developing efficient catalysts for the conversion of CO

Detection of specific genes related to drug action can provide scientific guidance for personalized medicine. Taking the detection of a single-nucleotide polymorphism (SNP) genotyping related to the chronic hepatitis B virus (HBV) therapy as an example, a novel biosensor with high sensitivity and selectivity was developed based on the hyperbranched rolling circle amplification (HRCA) in this work. The single-base mutant DNA (mutDNA) sequence can perfectly hybridize with the specially designed discrimination padlock probe and initiate the HRCA reaction. Subsequently, a great abundant of double-strand DNA sequences were released and a strong fluorescence signal can be detected after adding SYBR Green I. In particular, the enhanced fluorescence intensity exhibits a linear relationship with the logarithm of mutDNA concentration ranging from 0.1 nM to 40 nM with a low detection limit of 0.05 nM. However, when there was even a single base mismatch in the target DNA, the HRCA was suppressed and fluorescence response process could not occur, resulting in a high selectivity of this biosensor. Moreover, this detection strategy also performs well in human serums, demonstrating its potential application in detecting SNPs in real biological samples.

The possibility of using coinage metal atoms as excess electron acceptors is examined for the first time by designing a new class of M+-1-M′− (M = Li, Na, and K; M′ = Cu, Ag, and Au) compounds termed “coinage metalides” on the basis of an intriguing Janus-type all-cis1,2,3,4,5,6-hexafluorocyclohexane (1) molecule. Under the large facial polarization of 1, the outermost ns1 electrons of alkali metal atoms can be transferred to coinage metal atoms, forming diffuse excess electrons around them. Consequently, the resulting M+-1-Cu− and M+-1-Ag− compounds exhibit significantly large nonlinear optical (NLO) responses. In particular, these novel M+-1-M′− compounds exhibit much higher stability (larger VIEs and Ec values) than that of the corresponding M+·1·M′− (M, M′ = Li, Na, and K) alkalides. We hope this work could open up new possibilities for NLO material design by using coinage metal atoms as excess electron acceptors and, on the other hand, attract more experimental interest and efforts to synthesize such stable compounds in the laboratory.

Continued emphasis in the pharmaceutical industry toward development of hybrid and continuous processes has led to a resurgence in process analytical technologies. The need to consistently and rapidly monitor the quality of material being made from these processes is a significant challenge that requires integrated, online analytics. Often the most challenging aspect of implementing real-time monitoring is ensuring that the analytical instrumentation is receiving a representative sample from the process. The Small Molecule Design and Development organization at Eli Lilly and Company has developed a highly adaptable process-to-analytics interface that has been broadly implemented across the development portfolio. The automated sample carts use only gravity and low-pressure nitrogen to obtain representative process samples, typically on the order of 0.3–6 mL. Subsequent sample preparation operations including quenching, derivatization, and most commonly dilution (10–250× is customary, but not restrictive) i...

By substituting boron atoms for selected carbon atoms of a graphene quantum dot (GQD) model, namely a coronene molecule, the substituent effect on its geometric and electronic structure, as well as nonlinear optical response has been systemically investigated in theory. Our computations reveal that the boron substitution leads to a similar noncentrosymmetric apophysis structure for the boron-substituted coronene in singlet and triplet states. Noticeably, due to the small energy difference of 2.5 kcal mol-1 between the singlet and triplet states, the boron-substituted molecule can easily be switched between the antiferromagnetic (singlet state) and ferromagnetic (triplet state) state by slightly changing the external conditions. Notably, the boron-substituted coronene exhibits a considerably large first hyperpolarizability of 36241 au, because boron substitution yields a raised structure with an intermediate singlet diradical character. Hence, it is expected that this study not only provides new insights for the boron-substituent effect on the structure and properties of graphene but also may promote practical applications of GQDs in the fields of spintronics and nonlinear optics.

The possibility to design new superatom species by decorating Zintl polyanions with alkali metal cations has been examined under density functional theory in this work. Utilizing typical Zintl ions as examples, MLin+1+ cations have been constructed and investigated in detail. Calculations show that all of the Zintl anions Mn− preserve their geometric and electronic integrity in the global minima of MLin+1+ cations. The stability of these studied cations is guaranteed by the strong ionic bonds between the Zintl core and ligands, as well as their large HOMO−LUMO gaps and positive dissociation energies with respect to the loss of a Li+ cation. In particular, all these proposed cations possess pretty low vertical electron affinities, verifying their superalkali or pseudoalkali identities. Besides, the feasibility of using these proposed MLin+1+ cations as building blocks to design new superatom compounds is explored by theoretically constructing and charactering two series of MLin+1−(super)halogen compounds. We, therefore, hope that this work will not only provide an approach to obtain new superatoms by utilizing various Zintl polyanions as the central cores, but also offer new building blocks for cluster-assembled nanomaterials in which exceptionally strong reducing matters are required.

It has recently been demonstrated that oriented external electric fields (OEEFs) can serve as future smart reagents and effectors in chemistry. Consequently, the effect of OEEFs on the geometric structures, electronic properties, bonding properties, and NLO responses of three typical superatom compounds, i.e., (NLi4)(BF4) and (BLi6)X (X = BeF3 and BF4) has been systemically investigated by ab initio computations in this work. The computational results reveal that the (NLi4)(BF4) possesses almost the same performance as the traditional alkali metal halide under the same OEEFs. It is found that the vertical ionization potential, bond energy, and first hyperpolarizability of (NLi4)(BF4) can be gradually enhanced by increasing the imposed OEEF from zero to the critical external electric field (Fc) along the charge transfer direction (NLi4 → BF4). In particular, the first hyperpolarizability of (NLi4)(BF4) is greatly enlarged from 2.84 × 103 to 1.36 × 107 au (4790-fold) by increasing OEEF from 0 to 121 × 10–4 ...

The potential application of all-boron fullerene B40 as a drug carrier for anti-cancer nitrosourea (NU) has been explored by the means of density functional theory (DFT). Our results reveal that the NU drug tends to combine with the corner boron atom of B40 cage via its oxygen and nitrogen atoms with a moderate adsorption energy of −25.18 kcal/mol. Herein, the newly formed B-O and B-N bonds are proved to be strong polar covalent bonds by atoms in molecules (AIM) theory, localized molecular orbital (LMO), and electron localization function (ELF) analyses. A short recovery time of 52 s is predicted for the NU desorption process at 310.15 K, indicating that the desorption of NU from B40 is easy under body temperature. Moreover, it is found that B40 can simultaneously adsorb up to five NU drugs, exhibiting a high loading capacity. Finally, the substituent effect of C, N, Al, and Ga atoms on the drug delivery performance of this B40 nanocage has been considered. Our results not only suggest that B40 has a great potential to be used in drug delivery, but also signify that the substituent effect of foreign atoms can be employed to modulate the drug adsorption performance of B40.