A Comparative Study of the Effects of Electronic Cigarette and Traditional Cigarette on the Pulmonary Functions of C57BL/6 Male Mice.

INTRODUCTION: Electronic cigarettes (E-cigs) are in a controversial state. Although E-cig aerosol generally contains fewer harmful substances than smoke from burned traditional cigarettes, aerosol along with other compounds of the E-cigs may also affect lung functions and promote the development of lung-related diseases. We investigated the effects of E-cig on the pulmonary functions of male C57BL/6 mice and reveal the potential underlying mechanisms. METHODS: A total of 60 male C57BL/6 mice were randomly divided into four groups. They were exposed to fresh-air, traditional cigarette smoke, E-cig vapor with 12 mg/mL of nicotine, and E-cig with no nicotine for 8 weeks. Lung functions were evaluated by using quantitative analysis of the whole body plethysmograph, FlexiVent system, lung tissue histological and morphometric analysis, and RT-PCR analysis of mRNA expression of inflammation-related genes. In addition, the effects of nicotine and acrolein on the survival rate and DNA damage were investigated using cultured human alveolar basal epithelial cells. RESULTS: Exposure to E-cig vapor led to significant changes in lung functions and structures including the rupture of the alveolar cavity and enlarged alveolar space. The pathological changes were also accompanied by increased expression of interleukin-6 and tumor necrosis factor-α. CONCLUSIONS: The findings of the present study indicate that the safety of E-cig should be further evaluated. IMPLICATIONS: Some people currently believe that using nicotine-free E-cigs is a safe way to smoke. However, our research shows that E-cigs can cause lung damage regardless of whether they contain nicotine.

Development and therapeutic potential of DNA-dependent protein kinase inhibitors.

The deployment of DNA damage response (DDR) combats various forms of DNA damage, ensuring genomic stability. Cancer cells' propensity for genomic instability offers therapeutic opportunities to selectively kill cancer cells by suppressing the DDR pathway. DNA-dependent protein kinase (DNA-PK), a nuclear serine/threonine kinase, is crucial for the non-homologous end joining (NHEJ) pathway in the repair of DNA double-strand breaks (DSBs). Therefore, targeting DNA-PK is a promising cancer treatment strategy. This review elaborates on the structures of DNA-PK and its related large protein, as well as the development process of DNA-PK inhibitors, and recent advancements in their clinical application. We emphasize our analysis of the development process and structure-activity relationships (SARs) of DNA-PK inhibitors based on different scaffolds. We hope this review will provide practical information for researchers seeking to develop novel DNA-PK inhibitors in the future.

Discovery of plant-derived anti-tumor natural products: Potential leads for anti-tumor drug discovery.

Natural products represent a paramount source of novel drugs. Numerous plant-derived natural products have demonstrated potent anti-tumor properties, thereby garnering considerable interest in their potential as anti-tumor drugs. This review compiles an overview of 242 recently discovered natural products, spanning the period from 2018 to the present. These natural products, which include 69 terpenoids, 42 alkaloids, 39 flavonoids, 21 steroids, 14 phenylpropanoids, 5 quinolines and 52 other compounds, are characterized by their respective chemical structures, anti-tumor activities, and mechanisms of action. By providing an essential reference and fresh insights, this review aims to support and inspire researchers engaged in the fields of natural products and anti-tumor drug discovery.

MDM2 accelerated renal senescence via ubiquitination and degradation of HDAC1.

Senescence, an intricate and inevitable biological process, characterized by the gradual loss of homeostasis and declining organ functions. The pathological features of cellular senescence, including cell cycle arrest, metabolic disruptions, and the emergence of senescence-associated secretory phenotypes (SASP), collectively contribute to the intricate and multifaceted nature of senescence. Beyond its classical interaction with p53, murine double minute gene 2 (MDM2), traditionally known as an E3 ubiquitin ligase involved in protein degradation, plays a pivotal role in cellular processes governing senescence. Histone deacetylase (HDAC), a class of histone deacetylases mainly expressed in the nucleus, has emerged as a critical contributor to renal tissues senescence. In this study we investigated the interplay between MDM2 and HDAC1 in renal senescence. We established a natural aging model in mice over a 2-year period that was verified by SA-ß-GAL staining and increased expression of senescence-associated markers such as p21, p16, and TNF-α in the kidneys. Furthermore, we showed that the expression of MDM2 was markedly increased, while HDAC1 expression underwent downregulation during renal senescence. This phenomenon was confirmed in H2O2-stimulated HK2 cells in vitro. Knockout of renal tubular MDM2 alleviated renal senescence in aged mice and in H2O2-stimulated HK2 cells. Moreover, we demonstrated that MDM2 promoted renal senescence by orchestrating the ubiquitination and subsequent degradation of HDAC1. These mechanisms synergistically accelerate the aging process in renal tissues, highlighting the intricate interplay between MDM2 and HDAC1, underpinning the age-related organ function decline.

Comparison of neurally adjusted ventilatory assist and synchronized intermittent mandatory ventilation in preterm infants after patent ductus arteriosus ligation: a retrospective study.

OBJECTIVE: This study aimed to compare the efficacy of neurally adjusted ventilatory assist (NAVA) to synchronized intermittent mandatory ventilation (SIMV) in preterm infants requiring mechanical ventilation after patent ductus arteriosus (PDA) ligation. METHODS: A retrospective analysis was conducted on intubated preterm infants who underwent PDA ligation at our hospital from July 2021 to January 2023. Infants were divided into NAVA or SIMV groups based on the ventilation mode after surgery. RESULTS: Fifty preterm infants were included. During treatment, peak inspiratory pressure (PIP) and mean airway pressure (MAP) were lower with NAVA compared to SIMV (PIP: 19.1 ± 2.9 vs. 22.4 ± 3.6 cmH2O, P < 0.001; MAP: 9.1 ± 1.8 vs. 10.9 ± 2.7 cmH2O, P = 0.002). PaO2 and PaO2/FiO2 were higher with NAVA (PaO2: 94.0 ± 11.7 vs. 84.8 ± 15.8 mmHg, P = 0.031; PaO2/FiO2: 267 [220-322] vs. 232 [186-290] mmHg, P = 0.025). Less sedation was required with NAVA (midazolam: 1.5 ± 0.5 vs. 1.1 ± 0.3 µg/kg/min, P < 0.001). CONCLUSION: Compared to SIMV, early use of NAVA post PDA ligation in preterm infants was associated with decreased PIP and MAP. Early NAVA was also associated with reduced sedation needs and improved oxygenation. However, further studies are warranted to quantify the benefits of NAVA ventilation.

Clinical and Immunological Significance of ANKRD52 in Pan-Cancer.

Ankyrin repeat domain 52 (ANKRD52) is a regulatory component of the protein phosphatase 6 (PP6) holoenzyme. Evidence has emerged to suggest involvement of ANKRD52 in tumor metastases and cancer cell escape from T cell-mediated elimination and immunotherapy but there has been no research across different cancer types. The current study explored the biological functions of ANKRD52 by combining data from many databases. The aim was to expose new diagnostic or treatment biomarkers for malignant tumors. The roles of ANKRD52 with respect to immunotherapy in 33 human cancer types were analyzed by combining data from The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx), Cancer Cell Line Encyclopedia (CCLE), UCSC Xena, the Tumor Immune Estimation Resource (TIMER), TISIDB and Cellminer. Bioinformatics methods were used to analyze the association between ANKRD52 expression and prognosis, immunological indicators (immune cell infiltration, ESTIMATE scores and tumor microenvironment (TME) signatures), tumor mutational burden (TMB), microsatellite instability (MSI) and drug sensitivity. ANKRD52 expression was generally higher in 24 tumor tissues than in normal tissues and was associated with poor prognosis, especially in kidney chromophobe (KICH). Lower expression was observed in advanced cancer. ANKRD52 expression was strongly linked to major immunological indicators, such as immune cell infiltration, ESTIMATE scores, TME signatures, as well as expression of immune and tumor-related genes. Expression was also associated with indicators of immunotherapy efficacy and outcome, such as TMB in 7 cancer types and MSI in 12. In addition, ANKRD52 expression was linked to sensitivity to a number of anticancer drugs. ANKRD52 had a distinct immune function in breast invasive carcinoma (BRCA) that correlated negatively with most immune indicators. Expression was enriched in proliferation-, differentiation- and metabolism-related pathways and linked to other immune cells and TME signatures. A nomogram to predict 3- or 5-year overall survival (OS) of patients with BRCA was constructed. ANKRD52 may have utility as an oncological and immunological biomarker. New insights into oncogenesis are presented and the development of ANKRD52-targeting to increase the therapeutic efficacy of immunotherapy combined with chemotherapy explored.

Sublethal effect and detoxifying metabolism of metaflumizone and indoxacarb on the fall armyworm, Spodoptera frugiperda.

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera, Noctuidae), is a highly polyphagous invasive pest that damages various crops. Pesticide control is the most common and effective strategy to control FAW. In this study, we evaluated the toxicity of metaflumizone and indoxacarb against third-instar FAW larvae using the insecticide-incorporated artificial diet method under laboratory conditions. Both metaflumizone and indoxacarb exhibited substantial toxicity against FAW, with LC50 values of 2.43 and 14.66 mg/L at 72 h, respectively. The sublethal effects of metaflumizone and indoxacarb on parental and F1 generation FAW were investigated by exposing third-instar larvae to LC10 and LC30 concentrations of these insecticides. Sublethal exposure to these two insecticides significantly shortened adult longevity, extended pupal developmental times and led to reduced pupal weight, pupation rates, and adult fecundity in the treated parental generation and F1 generation at LC10 or LC30 concentrations, in comparison to the control group. The larval developmental times were shortened in the parental generation but prolonged in the F1 generation, after being treated with sublethal concentrations of metaflumizone. Furthermore, larvae exposed to LC10 or LC30 concentrations of indoxacarb exhibited elevated activity levels of cytochrome P450 monooxygenase and glutathione S-transferase, which coincides with the observed synergistic effect of piperonyl butoxide and diethyl maleate. In conclusion, the high toxicity and negative impact of metaflumizone and indoxacarb on FAW provided significant implications for the rational utilization of insecticides against this pest.

Prevention and Potential Treatment Strategies for Respiratory Syncytial Virus.

Respiratory syncytial virus (RSV) is a significant viral pathogen that causes respiratory infections in infants, the elderly, and immunocompromised individuals. RSV-related illnesses impose a substantial economic burden worldwide annually. The molecular structure, function, and in vivo interaction mechanisms of RSV have received more comprehensive attention in recent times, and significant progress has been made in developing inhibitors targeting various stages of the RSV replication cycle. These include fusion inhibitors, RSV polymerase inhibitors, and nucleoprotein inhibitors, as well as FDA-approved RSV prophylactic drugs palivizumab and nirsevimab. The research community is hopeful that these developments might provide easier access to knowledge and might spark new ideas for research programs.

Controllable Crystallization of Two-Dimensional Bi Nanocrystals with Morphology-Boosted CO2 Electroreduction in Wide pH Environments.

Two-dimensional low-melting-point (LMP) metal nanocrystals are attracting increasing attention with broad and irreplaceable applications due to their unique surface and topological structures. However, the chemical synthesis, especially the fine control over the nucleation (reduction) and growth (crystallization), of such LMP metal nanocrystals remains elusive as limited by the challenges of low standard redox potential, low melting point, poor crystalline symmetry, etc. Here, a controllable reduction-melting-crystallization (RMC) protocol to synthesize free-standing and surfactant-free bismuth nanocrystals with tunable dimensions, morphologies, and surface structures is presented. Especially, ultrathin bismuth nanosheets with flat or jagged surfaces/edges can be prepared with high selectivity. The jagged bismuth nanosheets, with abundant surface steps and defects, exhibit boosted electrocatalytic CO2 reduction performances in acidic, neutral, and alkaline aqueous solutions, achieving the maximum selectivity of near unity at the current density of 210 mA cm-2 for formate evolution under ambient conditions. This work creates the RMC pathway for the synthesis of free-standing two-dimensional LMP metal nanomaterials and may find broader applicability in more interdisciplinary applications.

Synergy-based functional electrical stimulation and robotic-assisted for retraining reach-to-grasp in stroke: a study protocol for a randomized controlled trial.

BACKGROUND: Stroke survivors have long-term upper limb impairment, which impacts the quality of life (QOL) and social reintegration, but there is lack of effective therapeutic strategies and novel technologies. Customized multi-muscle functional electrical stimulation (FES) based on the muscle synergy of healthy adults and robotic-assisted therapy (RAT) have been proved efficacy respectively. Synergy-based FES combined with RAT can be a novel and more effective therapy for upper limb recovery of stroke survivors from the perspective of synergistic enhancement. However, few studies have examined the effectiveness of combined synergy-based FES and RAT, especially for motor control evaluated by reach-to-grasp (RTG) movements. The main objective of the following research protocol is to evaluate the effectiveness and efficacy, as well as adoptability, of FES-RAT and FES or RAT rehabilitation program for upper limb function improvement after stroke. METHODS: This will be an assessor-blinded randomized controlled trial involving a 12-week intervention and a 6-month follow-up. Stratified randomization will be used to equally and randomly assign 162 stroke patients into the FES + conventional rehabilitation program (CRP) group, RAT + CRP group and FES-RAT + CRP group. Interventions will be provided in 5 sessions per week, with a total of 60 sessions. The primary outcome measurements will include the Fugl-Meyer Assessment and Biomechanical Assessment of RTG movements. The secondary outcome measurements will include quality of life and brain neuroplasticity assessments by MRI. Evaluations will be performed at five time points, including at baseline, 6 weeks and 12 weeks from the start of treatment, and 3 months and 6 months following the end of treatment. A two-way analysis of variance with repeated measures will be applied to examine the main effects of the group, the time factor and group-time interaction effects. DISCUSSION: The results of the study protocol will provide high quality evidence for integrated synergy-based FES and RAT, and synergy-based FES alone and guide the design of more effective treatment methods for stroke rehabilitation. TRIAL REGISTRATION: ChiCTR2300071588.

Microwave-assisted rapid synthesis of chiral oxazolines.

Chiral oxazoline compounds play an extremely important role in asymmetric synthesis and drug discovery. Herein a simpler, greener and more efficient microwave-assisted protocol to rapidly access chiral oxazolines is developed using aryl nitriles or cyano-containing compounds and chiral ß-amino alcohols as starting materials. The reaction proceeds smoothly in the presence of a recoverable heterogeneous catalyst in either concentrated solution or under solvent-free conditions. The advantages of this method include rapidness, convenience, environmental protection, high atom economy, and excellent yields. The protocol should find wider application in the community in the future.

Design, synthesis and anti-tumor efficacy evaluation of novel 1,3-diaryl propane-based polyphenols obtained from Claisen rearrangement reaction.

Polyphenols such as resveratrol, honokiol and nordihydroguaiaretic acid are widely existing in nature products or synthetic compounds with interesting biological activities. Inspired by their structural feature, a total of 49 1,3-diaryl propane-based polyphenols were designed and synthesized through Claisen rearrangement reaction. New compounds were initially assessed for their anti-proliferative activities against various cancer cell lines (PC-3, U87MG, U251, HCT116) at a concentration of 50 µM, and the results guided the SAR of this series of compounds. Further screening of selected compounds against seven cancer cell lines (three additional colon cancer cell lines namely COLO205, HT29 and SW480 were chosen) led to the identification of two advanced leads 2t and 3t with IC50 values ranging from 8.2 ± 0.1 to 19.3 ± 1.9 µM. Both compounds also showed promising anti-proliferative activities against COLO205 in dose- and time-dependent manners. Furthermore, 2t and 3t exhibited good anti-tumor efficacy in COLO205 xenografted mice model with TGI values ranging from 38% to 58%. These results warrant the further investigation of this series of compounds.

Effect of Different Types of Ossification of the Posterior Longitudinal Ligament on the Dynamic Biomechanical Response of the Spinal Cord: A Finite Element Analysis.

Ossification of the posterior longitudinal ligament (OPLL) has been identified as an important cause of cervical myelopathy. However, the biomechanical mechanism between the OPLL type and the clinical characteristics of myelopathy remains unclear. The aim of this study was to evaluate the effect of different types of OPLL on the dynamic biomechanical response of the spinal cord. A three-dimensional finite element model of the fluid-structure interaction of the cervical spine with spinal cord was established and validated. The spinal cord stress and strain, cervical range of motion (ROM) in different types of OPLL models were predicted during dynamic flexion and extension activity. Different types of OPLL models showed varying degrees of increase in stress and strain under the process of flexion and extension, and there was a surge toward the end of extension. Larger spinal cord stress was observed in segmental OPLL. For continuous and mixed types of OPLL, the adjacent segments of OPLL showed a dramatic increase in ROM, while the ROM of affected segments was limited. As a dynamic factor, flexion and extension of the cervical spine play an amplifying role in OPLL-related myelopathy, while appropriate spine motion is safe and permitted. Segmental OPLL patients are more concerned about the spinal cord injury induced by large stress, and patients with continuous OPLL should be noted to progressive injuries of adjacent level.

Knockdown of the glutamate-gated chloride channel gene decreases emamectin benzoate susceptibility in the fall armyworm, Spodoptera frugiperda.

Emamectin benzoate (EB), a derivative of avermectin, is the primary insecticide used to control the fall armyworm (FAW) in China. However, the specific molecular targets of EB against FAW remain unclear. In this study, we cloned the glutamate-gated chloride channel (GluCl) gene, which is known to be a primary molecular target for avermectin. We first investigated the transcript levels of SfGluCl in FAW and found that the expression level of SfGluCl in the head and nerve cord was significantly higher than that in other tissues. Furthermore, we found that the expression level of SfGluCl was significantly higher in eggs than that in other developmental stages, including larvae, pupae, and adults. Additionally, we identified three variable splice forms of SfGluCl in exons 3 and 9 and found that their splice frequencies remained unaffected by treatment with the LC50 of EB. RNAi mediated knockdown of SfGluCl showed a significant reduction of 42% and 65% after 48 and 72 h of dsRNA feeding, respectively. Importantly, knockdown of SfGluCl sifgnificantly reduced LC50 and LC90 EB treatment induced mortality of FAW larvae by 15% and 44%, respectively, compared to the control group feeding by dsEGFP. In contrast, there were no significant changes in the mortality of FAW larvae treated with the control insecticides chlorantraniliprole and spinetoram. Finally, molecular docking simulations revealed that EB bound to the large amino-terminal extracellular domain of SfGluCl by forming five hydrogen bonds, two alkyl hydrophobic interactions and one salt bridge. These findings strongly suggest that GluCl may serve as one of the molecular targets of EB in FAW, shedding light on the mode of action of this important insecticide.

The Chinese version of the Child Food Neophobia Scale and its reliability and validity in preschool children.

OBJECTIVE: To translate the English version Child Food Neophobia Scale (CFNS) into the Chinese version and test its reliability and validity in preschool children. METHODS: To create the Chinese version of the CFNS, it was translated, back-translated, and cross-culturally adapted. The use of the Chinese version of CFNS by 575 parents of preschool children in two kindergartens in Yangzhou City was investigated using cluster sampling to assess the reliability and validity of the scale. RESULTS: The Chinese version of CFNS has nine items in total. The scale-level average content validity index (S-CVI/Ave) is 0.983. Exploratory factor analysis (EFA) extracted 2 common factors, and the cumulative variance contribution rate was 49.437%. Confirmatory factor analysis (CFA) showed that the 2-factor model was well fitted. The Cronbach'α coefficient of the scale was 0.759, the Cronbach'α coefficients of the two factors were 0.735 and 0.713, the split-half reliability was 0.788, and the test-retest reliability was 0.756. CONCLUSION: The Chinese version of the Child Food Neophobia Scale has good reliability and validity in preschool children and can be used as an assessment tool for food neophobia in preschool children in China. PRACTICE IMPLICATIONS: This study has gone through a rigorous translation process, and the CFNS may support future exploration of food neophobia in preschool children. Food allergy factors in the results may be the next step in the research, and several studies are still needed to understand the relationship between food allergy and food neophobia.

Tetrahedral Imidazolate Frameworks with Auxiliary Ligands (TIF-Ax): Synthetic Strategies and Applications.

Zeolitic imidazolate frameworks (ZIFs) are an important subclass of metal-organic frameworks (MOFs). Recently, we reported a new kind of MOF, namely tetrahedral imidazolate frameworks with auxiliary ligands (TIF-Ax), by adding linear ligands (Hint) into the zinc-imidazolate system. Introducing linear ligands into the M2+-imidazolate system overcomes the limitation of imidazole derivatives. Thanks to the synergistic effect of two different types of ligands, a series of new TIF-Ax with interesting topologies and a special pore environment has been reported, and they have attracted extensive attention in gas adsorption, separation, catalysis, heavy metal ion capture, and so on. In this review, we give a comprehensive overview of TIF-Ax, including their synthesis methods, structural diversity, and multi-field applications. Finally, we also discuss the challenges and perspectives of the rational design and syntheses of new TIF-Ax from the aspects of their composition, solvent, and template. This review provides deep insight into TIF-Ax and a reference for scholars with backgrounds of porous materials, gas separation, and catalysis.

Emerging Biopharmaceuticals from Pimpinella Genus.

Evolved over eons to encode biological assays, plants-derived natural products are still the first dawn of drugs. Most researchers have focused on natural compounds derived from commonly used Pimpinella species, such as P. anisum, P. thellungiana, P. saxifrage, and P. brachycarpa, to investigate their antioxidant, antibacterial, and anti-inflammatory properties. Ethnopharmacological studies demonstrated that the genus Pimpinella has the homology characteristics of medicine and food and mainly in the therapy of gastrointestinal dysfunction, respiratory diseases, deworming, and diuresis. The natural product investigation of Pimpinella spp. revealed numerous natural products containing phenylpropanoids, terpenoids, flavonoids, coumarins, sterols, and organic acids. These natural products have the potential to provide future drugs against crucial diseases, such as cancer, hypertension, microbial and insectile infections, and severe inflammations. It is an upcoming field of research to probe a novel and pharmaceutically clinical value on compounds from the genus Pimpinella. In this review, we attempt to summarize the present knowledge on the traditional applications, phytochemistry, and pharmacology of more than twenty-five species of the genus Pimpinella.

Genome-wide identification and expression analysis of JmjC domain-containing genes in grape under MTA treatment.

Histone demethylases containing the JmjC domain play an extremely important role in maintaining the homeostasis of histone methylation and are closely related to plant growth and development. Currently, the JmjC domain-containing proteins have been reported in many species; however, they have not been systematically studied in grapes. In this paper, 21 VviJMJ gene family members were identified from the whole grape genome, and the VviJMJ genes were classified into five subfamilies: KDM3, KDM4, KDM5, JMJD6, and JMJ-only based on the phylogenetic relationship and structural features of Arabidopsis and grape. After that, the conserved sites of VviJMJ genes were revealed by protein sequence analysis. In addition, chromosomal localization and gene structure analysis revealed the heterogeneous distribution of VviJMJ genes on grape chromosomes and the structural features of VviJMJ genes, respectively. Analysis of promoter cis-acting elements demonstrated numerous hormone, light, and stress response elements in the promoter region of the VviJMJ genes. Subsequently, the grape fruit was treated with MTA (an H3K4 methylation inhibitor), which significantly resulted in the early ripening of grape fruits. The qRT-PCR analysis showed that VviJMJ genes (except VviJMJ13c) had different expression patterns during grape fruit development. The expression of VviJMJ genes in the treatment group was significantly higher than that in the control group. The results indicate that VviJMJ genes are closely related to grape fruit ripening.

Design, synthesis and antitumor efficacy evaluation of a series of novel ß-elemene-based macrocycles.

ß-Elemene is the major constituent of the antitumor drugs elemene extract approved in China. By incorporating macrocyclization strategy into the ß-elemene skeleton, we designed a series of novel macrocycles retaining three key carbon-carbon double bonds. Four different methods have been successfully developed for these challenging ring systems. A total of twenty-eight 14- to 24-membered macrocycles were synthesized. Most of these macrocycles exhibited good antitumor activity against several cancer cell lines (PC-3, A549, U87MG, U251 and HCT116), with up to 40 folds improvement of activity comparing to ß-elemene. Additionally, X-ray single crystal structures of compounds Ic, Ip, and IIh were successfully solved as the proof of macrocycle formation. The results warrant the further investigation of this novel class macrocycles in pharmacokinetic and pharmacodynamics studies, which will be reported in due course.

Fast on-line rubidium DPAL atomic concentration measurement by 420 nm probe laser: erratum.

We present an erratum to our recent work [Appl. Opt.60, 10862 (2021)APOPAI0003-693510.1364/AO.440435] that corrects errors in Fig. 4 and the body of the paper. The corrections do not affect the results and conclusions of the original paper.