Dissociative charge exchange re-actions between Ar^(+)ion and trans-/cis-dichloroethylene(trans-/cis-C_(2)H_(2)Cl_(2))are investi-gated with the ion-velocity imag-ing technique.The dechlorinated product C_(2)H_(2)Cl^(...Dissociative charge exchange re-actions between Ar^(+)ion and trans-/cis-dichloroethylene(trans-/cis-C_(2)H_(2)Cl_(2))are investi-gated with the ion-velocity imag-ing technique.The dechlorinated product C_(2)H_(2)Cl^(+)is the predomi-nant,and most of this product show the spatial distribution around the target,implying that the dissociation occurs in the large impact-parameter collision and via the energy resonant charge transfer.Meanwhile,a few C_(2)H_(2)Cl^(+)locate around the center-of-mass,which is at-tributed to the fragmentation of intimate association between C_(2)H_(2)Cl_(2)and Ar^(+)or in the small impact-parameter collision.The product C_(2)HCl_(+)exhibits the velocity distribution fea-tures similar to those of C_(2)H_(2)Cl_(+).The rarest product C_(2)HCl_(2)+shows the distributions around the molecular target,due to the quick dehydrogenation after the energy-resonant charge transfer in the large impact-parameter collision.展开更多
To facilitate gathering information during a psychiatric interview, some psychiatrists advocate augmenting the interview using drugs. Rather than barbiturates, benzodiazepines have been used for drug-assisted intervie...To facilitate gathering information during a psychiatric interview, some psychiatrists advocate augmenting the interview using drugs. Rather than barbiturates, benzodiazepines have been used for drug-assisted interviews. Dissociative amnesia is one of the indications for these interviews. Herein, we present the case of a 15-year-old female who was diagnosed as having dissociative amnesia because of conflicts with her friends. She was administered a Iorazepam-assisted interview to aid recovery of her memories. In this case, a small dose of Iorazepam was sufficient to recover her memories without any adverse effects.展开更多
Background Childhood trauma(CT)is an important risk factor in the emergence and clinical course of psychiatric disorders.In the latest literature,an association exists between CT and patients with schizophrenia.There ...Background Childhood trauma(CT)is an important risk factor in the emergence and clinical course of psychiatric disorders.In the latest literature,an association exists between CT and patients with schizophrenia.There is also a strong relationship between the dissociative symptoms of schizophrenia and the presence of CT.Aims The aim of this study is to examine the relationship between CT and dissociative,positive and negative symptoms in patients with schizophrenia.Methods One hundred patients with schizophrenia and 100 healthy volunteers were included in the study.The Sociodemographic Data Form,Dissociative Experiences Scale(DES),Positive and Negative Syndrome Scale(PANSS),and Childhood Trauma Questionnaire(CTQ)were administered to all participants.Results The CTQ and DES scores of the schizophrenia group were significantly higher than those of the control group.In patients with schizophrenia,a positive association was found between positive symptoms and DES scores.In terms of negative symptoms,a positive association was found between apathetic social withdrawal and CTQ-emotional neglect(EN),CTQ-physical neglect(PN)and CTQ total scores.There was a significant positive correlation between CTQ-EN scores and negative symptoms and PANSS scores.No significant relationship was found between negative symptoms and DES scores.Conclusions High rates of CT and dissociative symptoms are seen in patients with schizophrenia.In addition,the findings of the relationship between CT and dissociative,positive and negative symptoms are also noteworthy.Therefore,it may be important for clinicians to assess trauma history during the psychiatric evaluation of patients with schizophrenia.展开更多
One of the important effects of the ionospheric modification by high-power waves is the airglow enhancement. Both the thermal electrons and the dissociation recombination contribute to generate the airglow emissions d...One of the important effects of the ionospheric modification by high-power waves is the airglow enhancement. Both the thermal electrons and the dissociation recombination contribute to generate the airglow emissions during HF heating. However, the relative importance of the airglow emission induced by dissociative recombination and thermal electrons has been rarely investigated. In this study, we carry out a simulation study on the airglow produced by high-power HF heating at nighttime associated with dissociative recombination and thermal electrons. SAMI2(Sami2 is Another Model of the Ionosphere) is employed to simulate the ionospheric variations during the HF heating. The main conclusions from this study are as follows:(1) For the airglow induced by dissociative recombination, both 630.0 nm and 557.7 nm emissions show a decrease at the heating wave reflection height during the heating period,while when the heating is turned off, an increase is shown at lower altitudes. The reduction of airglow during the heating is caused by the rapid increase of electron temperature and the diffusion of plasmas dominates the after-heating airglow enhancement.(2) 630.0 nm emission due to thermal electrons is greatly enhanced at the wave reflection height, indicating that thermal electrons play a major role in exciting 630.0 nm emission. For the 557.7 nm emission, the excitation threshold(4.17 e V) is too high for thermal electrons.(3) The combined effect of dissociative recombination and thermal electrons could be the possible reason for the observed X-mode(extraordinary mode) suppression of 630.0 nm airglow during O-mode(ordinary mode) enhancement.展开更多
The dissociative ionization of CO2 induced by 5 keV electrons in two-body and three-body dissociative channels of CO2+2 and CO3+2 is identified by the ion-ion coincidence- method using a momentum imaging spectromete...The dissociative ionization of CO2 induced by 5 keV electrons in two-body and three-body dissociative channels of CO2+2 and CO3+2 is identified by the ion-ion coincidence- method using a momentum imaging spectrometer. The partial ionization cross sections (PICSs) of different ionic fragments are measured and the results generally agree with the calculations made by a semi-empirical approach. Furthermore, the PICSs of the dissociative channels are also obtained by carefully considering the detection efficiency of the micro-channel plates and the total transmission efficiency of the time of flight system.展开更多
The field-ionization Coulomb explosion model is extended to investigate the multielectron dissociative ionization process of N2 molecule irradiated by an intense femtosecond laser field with an arbitrary polarization....The field-ionization Coulomb explosion model is extended to investigate the multielectron dissociative ionization process of N2 molecule irradiated by an intense femtosecond laser field with an arbitrary polarization. The ionization process of N2 molecule is found to be optimal at the critical internuclear distance Rc=7a.u., which is independent of the laser polarization state, the molecular explosion channel and the angle between the molecular axis and the direction of laser electric field. The kinetic energies of the ion fragments are identical in the cases of linear and circular polarizations at the same incident laser intensity. However, the probability of electron ionization is very sensitive to the above three parameters. At the critical distance Rc=7a.u. the angular dependence of the threshold intensity for the over-the-barrier ionization leads to the geometric alignment of molecules in the case of linear polarization. The threshold intensity in the case of circular polarization is apparently higher than that in the case of linear polarization, which can well explain the significant decrease of ionization in the case of circular polarization. The numerical calculations are compared with the experimental measurements.展开更多
Dissociative convulsions, a prominent form of dissociative (conversion) disorder formerly known as hysteria, are a common and elusive differential diagnosis from epilepsy. However, the treatment of such patients is al...Dissociative convulsions, a prominent form of dissociative (conversion) disorder formerly known as hysteria, are a common and elusive differential diagnosis from epilepsy. However, the treatment of such patients is always challenging and frustrating due to poor response to the routinely used interventions in most situations. Here, we present a case with dissociative convulsions in order to catch the eye of the clinicians and researchers on the recognition of clinical manifestation and exploration of therapeutic strategies.展开更多
Objective: Current randomized clinical trial was conducted to compare the efficacy and side effects of dissociative conscious sedation and conscious sedation in patients under bronchoscopy. Methods: In this randomized...Objective: Current randomized clinical trial was conducted to compare the efficacy and side effects of dissociative conscious sedation and conscious sedation in patients under bronchoscopy. Methods: In this randomized clinical trial, 110 patients scheduled for Fiberoptic Bronchoscopy in a training hospital in 2012 were enrolled and randomly assigned to receive either SC ketamine plus IV fentanyl (dissociative conscious sedation) or placebo plus IV fentanyl (conscious sedation) and the efficacy and side effects were assessed and compared. Results: There was significant difference between systolic and diastolic blood pressure and heart rate in two groups and more stability was shown in dissociative conscious sedation group (P < 0.05). Also the incidence of cough, the need to extra dose of fentanyl and recall showed less frequency in dissociative conscious sedation group (P < 0.05). Conclusions: Totally, according to the obtained results, it may be concluded that Subcutaneous Dissociative Conscious Sedation (sDCS) in comparison to Conscious Sedation is significantly more efficient accompanied by less side effects in fiberoptic bronchoscopy and using this method is recommended. Implication of the Manuscript: The study was designed in order to evaluate the efficacy of subcutaneous Dissociative Conscious Sedation (sDCS) Method in fiberoptic bronchoscopy.展开更多
Purpose: Anesthesia and airway management for mediastinal masses are challenging and are accompanied by mortality and morbidity. Avoiding the loss of airway muscular tone in mediastinal masses has been confirmed neces...Purpose: Anesthesia and airway management for mediastinal masses are challenging and are accompanied by mortality and morbidity. Avoiding the loss of airway muscular tone in mediastinal masses has been confirmed necessary to avoid airway collapse. Sufficient spontaneous ventilation is of paramount importance in order to reduce the rate of mortality and morbidity. Various anesthetics and anesthesia techniques have been used for maintaining spontaneous ventilation and patent airway. In this report, a successful double lumen endobronchial intubation using “subcutaneous dissociative conscious sedation” as a novel method in the management of compromised airway (a case of a mediastinal mass) is presented. Clinical features: A 42 year- old, 62 Kg man was presented for an open biopsy of a middle mediastinal mass. The patient had a history of chest pain, dyspnea, cough, fever and sweats for 2 months. Regarding to the life threatening nature of mediastinal masses resulting from unpredictable events of airway obstruction and the reported cases of deaths after induction of anesthesia in patients with mediastinal masses and regarding to the importance of not losing muscular tone and keeping airway tone intact in patients with mediastinal masses” subcutaneous Dissociative Conscious Sedation (a novel method of anesthesia)”was selected in order to guarantee the safety of the patient and keep the airway secure. Conclusion: Owing to the characteristics of the “subcutaneous dissociative conscious sedation” this method is suggested as an appropriate substitute to general anesthesia for Endobronchial Double Lumen Intubation in mediastinal masses and compromised airway.展开更多
In situ Raman spectroscopic and voltammetric studies indicate that dissociative adsorption of methanol on the rough platinum electrode occurs in the hydrogen ad/desorption potential range, and the dissociative extent ...In situ Raman spectroscopic and voltammetric studies indicate that dissociative adsorption of methanol on the rough platinum electrode occurs in the hydrogen ad/desorption potential range, and the dissociative extent depends on the initial potential of the electrode before contacting methanol, in addition to the contacting time. As the dissociative product, carbon monoxide competes the site of strongly bound hydrogen preferentially, and shifts the ad/desorption potentials of weakly bound hydrogen towards more positive ones gradually with the increase of CO coverage. Whereas, formaldehyde dissociates more easily by far and completely suppresses H-adsorption. The confocal Raman spectroscopy developed on transition metals shows some intriguing advantages in investigating electrocatalytic oxidation of small organic molecules.展开更多
The foreign accent syndrome(FAS) is a rare speech disorder, characterised by the appearance of a new accent, different from the speaker's native language and perceived as foreign by others. In the majority of pati...The foreign accent syndrome(FAS) is a rare speech disorder, characterised by the appearance of a new accent, different from the speaker's native language and perceived as foreign by others. In the majority of patients, FAS is secondary to focal brain damage caused by stroke or other neurological disorders. Infrequently, FAS has been reported in association with psychiatric disorders, including dissociative or conversion disorders. The case of a young woman with recurrent episodes of speaking with a foreign accent is described. Repeated neurological examinations, imaging and electroencephalography did not reveal any brain abnormality. However, there was a history of a difficult childhood, alcohol dependence in the father, parental discord, alleged sexual abuse in the past, interpersonal difficulties and parental death. Episodes were precipitated by stressful life circumstances and resolved spontaneously, or with supportive treatment. She had additional "suspect" symptoms such as non-epileptic seizures, aphonia and motor paralysis. All these features indicated that a dissociative disorder was involved in the genesis of her FAS. The influence of external factors such as the media was unclear. Generally biological factors have been implicated in the onset of FAS, but the presentation in this young woman suggests that psychological factors such as personality, trauma, stressful life events and psychiatric disorder; familial factors such as parental discord and parental death and family conflicts; and, social factors such the possible influence of the media may also be involved in the production of foreign accents by patients.展开更多
Despite outstanding improvements in anesthesia techniques and anesthetics, difficult airway is still a dilemma and is accompanied by morbidity and mortality. The aim of this study is to compare the feasibility of endo...Despite outstanding improvements in anesthesia techniques and anesthetics, difficult airway is still a dilemma and is accompanied by morbidity and mortality. The aim of this study is to compare the feasibility of endotracheal intubation with the traditional method of general anesthesia by using muscle relaxants, and “sDCS” (Subcutaneous Dissociative Conscious Sedation) which has been recently reported as an efficient method of anesthesia with the capability of maintaining spontaneous ventilation and providing an appropriate situation for larynxgoscopy and endotracheal intubation. Material and Methods: This randomized clinical trial was conducted on 100 patients who were scheduled for elective laparotomy. Patients were randomly divided into two groups: group A and group B. In group A, patients underwent general anesthesia with thiopental sodium and relaxant. In group B, patients underwent “subcutaneous Dissociative Conscious Sedation” and received low dose subcutaneous ketamine and intravenous narcotic with no relaxant. The feasibility of direct laryngoscopy and tracheal intubation, hemodynamic changes, desaturation (SpO2 < 90%), patient cooperation, patient comfort, hallucination, nausea and vomiting, nystagmus and salivation were evaluated in two groups. Adverse events including apnea and need for positive pressure mask ventilation, additional dose of fentanyl were recorded in group B. The anesthesiologist who performed the procedure was asked about the patient calmness and cooperation during the procedure and the feasibility of laryngoscopy and tracheal intubation. The incidence of nausea and vomiting in post-operative care unit was recorded too. Results: Hemodynamic variables were comparable in two groups. No event of irreversible respiratory depression, desaturation, need for positive pressure ventilation and hallucination was observed in group B. All patients were cooperative and obedient during the laryngoscopy and tracheal intubation. The incidence of nausea was not statistically significant. The anesthesiologist was satisfied by the quality of patient’s cooperation for laryngoscopy in both groups. Conclusion: Subcutaneous dissociative conscious sedation is comparable with general anesthesia to provide desirable situation for laryngoscopy and tracheal intubation.展开更多
Background: Dissociation may be defined as a psychopathological process in which an individual’s psyche splits into two or more parts. The division of personality is a key element in trauma, especially if the patient...Background: Dissociation may be defined as a psychopathological process in which an individual’s psyche splits into two or more parts. The division of personality is a key element in trauma, especially if the patient is not able to cope with it. At least one part of personality may be relatively able to understand and function in the objective reality, whilst other part(s) of the psyche may be more or less disorganized, dysfunctional and less able to understand the truth. Methods: literature review;conceptualization of dissociation, dissociative disorders and partial psychosis from medical and philosophical perspective. Conclusion: The core of dissociation and dissociative disorders is usually psychological trauma, especially emotional trauma, although some individuals may experience dissociation without any obvious cause or trigger. Carefully designed trauma-focused psychotherapy and psychosocial support are considered and must be further studied as the cornerstone of multidisciplinary approach in the treatment of dissociative disorders. Dissociative identity disorder in its severe form may resemble characteristics of partial psychosis. Some patients suffering from partial psychosis have narcissistic personality traits, such as shamelessness, magical thinking, arrogance, envy, entitlement, exploitation and bad boundaries, and therefore, developing healthy self-love, which is based on healthy self-criticism, realistic thinking, humility, gratefulness, democratic behavior, altruism and good boundaries, might be helpful for these patients.展开更多
Using first-principles calculations, we systematically study the potential energy surfaces and dissociation processes of the hydrogen molecule on the Mg(0001) surface. It is found that during the dissociative adsorp...Using first-principles calculations, we systematically study the potential energy surfaces and dissociation processes of the hydrogen molecule on the Mg(0001) surface. It is found that during the dissociative adsorption process with the minimum energy barrier, the hydrogen molecule first orients perpendicularly, and then rotates tobecome parallel to the surface. It is also found that the orientation of the hydrogen molecule in the transition state is neither perpendicular nor parallel to the surface. Most importantly we find that the rotation causes a reduction of the calculated dissociation energy barrier for the hydrogen molecule. The underlying electronic mechanism for the rotation of the hydrogen molecule is also discussed in the paper.展开更多
Borderline personality disorder, conversion disorder and obsessive compulsive disorder frequently have dissociative symptoms. The literature has demonstrated that the level of dissociation might be correlated with the...Borderline personality disorder, conversion disorder and obsessive compulsive disorder frequently have dissociative symptoms. The literature has demonstrated that the level of dissociation might be correlated with the severity of obsessive compulsive disorder(OCD) and that those not responding to treatment had high dissociative symptoms. The structured clinical interview for DSM-IV dissociative disorders, dissociation questionnaire, somatoform dissociation questionnaire and dissociative experiences scale can be used for screening dissociative symptoms and detecting dissociative disorders in patients with OCD. However, a history of neglect and abuse during childhood is linked to a risk factor in the pathogenesis of dissociative psychopathology in adults. The childhood trauma questionnaire-53 and childhood trauma questionnaire-40 can be used for this purpose. Clinicians should not fail to notice the hidden dissociative symptoms and childhood traumatic experiences in OCD cases with severe symptoms that are resistant to treatment. Symptom screening and diagnostic tools used for this purpose should be known. Knowing how to treat these pathologies in patients who are diagnosed with OCD can be crucial.展开更多
We extend the hotspot model to include the virtuality dependence and use it to study the exclusive and dissociative J/Ψ production combined with the dipole amplitude in the target rapidity representation.We determine...We extend the hotspot model to include the virtuality dependence and use it to study the exclusive and dissociative J/Ψ production combined with the dipole amplitude in the target rapidity representation.We determined that virtuality takes effect on a number of hotspots,thus providing a better description of the J/Ψ production data at HERA.The collinear improved Balitsky-Kovchegove equation in the target rapidity representation is numerically solved and used to fit the J/Ψ experimental data with a series of hotspot sizes.We infer that virtuality significantly influences the number and size of hotspots.The expression χ^(2)/d.o.f=1.0183 resulting from the fit with the collinear improved dipole amplitude in the target rapidity representation is more reasonable than the correspondingχ^(2)/d.o.f=1.3995 originating from the leading order fit,which indicates that the collinear improved evolution equation in the target rapidity representation can provide a relatively good depiction of the exclusive and dissociative HERA data.展开更多
Much progress has been achieved for both experimental and theoretical studies on the dissociative chemisorption of molecules on surfaces.Quantum state-resolved experimental data has provided unprecedented details for ...Much progress has been achieved for both experimental and theoretical studies on the dissociative chemisorption of molecules on surfaces.Quantum state-resolved experimental data has provided unprecedented details for these fundamental steps in heterogeneous catalysis,while the quantitative dynamics is still not fully understood in theory.An in-depth understanding of experimental observations relies on accurate dynamical calculations,in which the potential energy surface and adequate quantum mechanical implementation are desired.This article summarizes the current methodologies on the construction of potential energy surfaces and the quantum mechanical treatments,some of which are promising for future applications.The challenges in this field are also addressed.展开更多
I. INTRODUCTION The chemisorption characteristics and reactivity near the ledge on the stepped surface as a defect on solid surface are worth noticing. In many cases, defects on metal surface not only control the adso...I. INTRODUCTION The chemisorption characteristics and reactivity near the ledge on the stepped surface as a defect on solid surface are worth noticing. In many cases, defects on metal surface not only control the adsoprtion rate of the gas molecule, but also have an impotant influence on the formation of a veriety of catalysates. For example, studying the catalytic oxidation展开更多
In the present paper we study the kinetics of dissociative adsorption of formic acid on the electrode of tetrahexahedral platinum nanocrystals (THH Pt NCs). In situ FTIR spectroscopic results demonstrate that HCOOH ca...In the present paper we study the kinetics of dissociative adsorption of formic acid on the electrode of tetrahexahedral platinum nanocrystals (THH Pt NCs). In situ FTIR spectroscopic results demonstrate that HCOOH can be oxidized to CO2 at a low potential (-0.2 V(SCE)) on the THH Pt NCs electrode, and the chemical bonds inside formic acid molecule are broken to form adsorbed COL species. The kinetics of the dissociative adsorption of HCOOH was quantitatively investigated by employing programmed potential step technique. It has been determined that, in 5 × 10-3 mol·L-1 HCOOH + 0.1 mol·L-1 H2SO4 solution, the maximal value of the average rate (υamax) of dissociative adsorption of HCOOH on a commercial Pt/C catalyst electrode is 8.58 × 10-10 mol·cm-2·s-1, while on the THH Pt NCs the υamax is 1.5 times larger than the υamax measured on Pt/C and reaches 13.19 × 10-10 mol·cm-2·s-1. The results have revealed that the reactivity of the THH Pt NCs is much higher than that of the Pt/C catalysts.展开更多
Ⅰ. INTRODUCTIONSome experiments showed that after forming graphite monolayer, the catalytic activites of some metal catalysts were reduced and lost. But mechanism of this process is still poorly understood. On the ot...Ⅰ. INTRODUCTIONSome experiments showed that after forming graphite monolayer, the catalytic activites of some metal catalysts were reduced and lost. But mechanism of this process is still poorly understood. On the other hand, the reaction of hydrogengraphite system plays an important role in the field of exploiting and the use of energy source. Therefore, this system has attracted attention in further studying the kinetics of its reaction. Demidovish et al. studied EPR on the dissociative adsorption of H<sub>2</sub> on graphite surfacet. Dihydrogen recombination, being an inverse展开更多
基金supported by the National Natural Sci-ence Foundation of China(No.22003062 and No.21625301)the Chinese Academy of Sciences(No.YZ201565).
文摘Dissociative charge exchange re-actions between Ar^(+)ion and trans-/cis-dichloroethylene(trans-/cis-C_(2)H_(2)Cl_(2))are investi-gated with the ion-velocity imag-ing technique.The dechlorinated product C_(2)H_(2)Cl^(+)is the predomi-nant,and most of this product show the spatial distribution around the target,implying that the dissociation occurs in the large impact-parameter collision and via the energy resonant charge transfer.Meanwhile,a few C_(2)H_(2)Cl^(+)locate around the center-of-mass,which is at-tributed to the fragmentation of intimate association between C_(2)H_(2)Cl_(2)and Ar^(+)or in the small impact-parameter collision.The product C_(2)HCl_(+)exhibits the velocity distribution fea-tures similar to those of C_(2)H_(2)Cl_(+).The rarest product C_(2)HCl_(2)+shows the distributions around the molecular target,due to the quick dehydrogenation after the energy-resonant charge transfer in the large impact-parameter collision.
文摘To facilitate gathering information during a psychiatric interview, some psychiatrists advocate augmenting the interview using drugs. Rather than barbiturates, benzodiazepines have been used for drug-assisted interviews. Dissociative amnesia is one of the indications for these interviews. Herein, we present the case of a 15-year-old female who was diagnosed as having dissociative amnesia because of conflicts with her friends. She was administered a Iorazepam-assisted interview to aid recovery of her memories. In this case, a small dose of Iorazepam was sufficient to recover her memories without any adverse effects.
文摘Background Childhood trauma(CT)is an important risk factor in the emergence and clinical course of psychiatric disorders.In the latest literature,an association exists between CT and patients with schizophrenia.There is also a strong relationship between the dissociative symptoms of schizophrenia and the presence of CT.Aims The aim of this study is to examine the relationship between CT and dissociative,positive and negative symptoms in patients with schizophrenia.Methods One hundred patients with schizophrenia and 100 healthy volunteers were included in the study.The Sociodemographic Data Form,Dissociative Experiences Scale(DES),Positive and Negative Syndrome Scale(PANSS),and Childhood Trauma Questionnaire(CTQ)were administered to all participants.Results The CTQ and DES scores of the schizophrenia group were significantly higher than those of the control group.In patients with schizophrenia,a positive association was found between positive symptoms and DES scores.In terms of negative symptoms,a positive association was found between apathetic social withdrawal and CTQ-emotional neglect(EN),CTQ-physical neglect(PN)and CTQ total scores.There was a significant positive correlation between CTQ-EN scores and negative symptoms and PANSS scores.No significant relationship was found between negative symptoms and DES scores.Conclusions High rates of CT and dissociative symptoms are seen in patients with schizophrenia.In addition,the findings of the relationship between CT and dissociative,positive and negative symptoms are also noteworthy.Therefore,it may be important for clinicians to assess trauma history during the psychiatric evaluation of patients with schizophrenia.
基金supported by the National Natural Science Foundation of China(41325017,41274158,41274157,and 41421063)the fundamental research funds for the central universitiesThousand Young Talents Program of China
文摘One of the important effects of the ionospheric modification by high-power waves is the airglow enhancement. Both the thermal electrons and the dissociation recombination contribute to generate the airglow emissions during HF heating. However, the relative importance of the airglow emission induced by dissociative recombination and thermal electrons has been rarely investigated. In this study, we carry out a simulation study on the airglow produced by high-power HF heating at nighttime associated with dissociative recombination and thermal electrons. SAMI2(Sami2 is Another Model of the Ionosphere) is employed to simulate the ionospheric variations during the HF heating. The main conclusions from this study are as follows:(1) For the airglow induced by dissociative recombination, both 630.0 nm and 557.7 nm emissions show a decrease at the heating wave reflection height during the heating period,while when the heating is turned off, an increase is shown at lower altitudes. The reduction of airglow during the heating is caused by the rapid increase of electron temperature and the diffusion of plasmas dominates the after-heating airglow enhancement.(2) 630.0 nm emission due to thermal electrons is greatly enhanced at the wave reflection height, indicating that thermal electrons play a major role in exciting 630.0 nm emission. For the 557.7 nm emission, the excitation threshold(4.17 e V) is too high for thermal electrons.(3) The combined effect of dissociative recombination and thermal electrons could be the possible reason for the observed X-mode(extraordinary mode) suppression of 630.0 nm airglow during O-mode(ordinary mode) enhancement.
基金supported by the National Basic Research Program of China(Grant No.2010CB923301)the National Natural Science Foundation of China(Grant Nos.11327404,10979007,and 10734040)the Fundamental Research Funds for the Central Universities,China
文摘The dissociative ionization of CO2 induced by 5 keV electrons in two-body and three-body dissociative channels of CO2+2 and CO3+2 is identified by the ion-ion coincidence- method using a momentum imaging spectrometer. The partial ionization cross sections (PICSs) of different ionic fragments are measured and the results generally agree with the calculations made by a semi-empirical approach. Furthermore, the PICSs of the dissociative channels are also obtained by carefully considering the detection efficiency of the micro-channel plates and the total transmission efficiency of the time of flight system.
基金Project supported by the National Key Basic Research Special Foundation (NKBRSF) (Grant No TG1999075207) and the National Natural Science Foundation of China (Grant Nos 10104003, 90206003 and 60378012) and the China Postdoctoral Science Foundation (Grant No 2003034093).
文摘The field-ionization Coulomb explosion model is extended to investigate the multielectron dissociative ionization process of N2 molecule irradiated by an intense femtosecond laser field with an arbitrary polarization. The ionization process of N2 molecule is found to be optimal at the critical internuclear distance Rc=7a.u., which is independent of the laser polarization state, the molecular explosion channel and the angle between the molecular axis and the direction of laser electric field. The kinetic energies of the ion fragments are identical in the cases of linear and circular polarizations at the same incident laser intensity. However, the probability of electron ionization is very sensitive to the above three parameters. At the critical distance Rc=7a.u. the angular dependence of the threshold intensity for the over-the-barrier ionization leads to the geometric alignment of molecules in the case of linear polarization. The threshold intensity in the case of circular polarization is apparently higher than that in the case of linear polarization, which can well explain the significant decrease of ionization in the case of circular polarization. The numerical calculations are compared with the experimental measurements.
文摘Dissociative convulsions, a prominent form of dissociative (conversion) disorder formerly known as hysteria, are a common and elusive differential diagnosis from epilepsy. However, the treatment of such patients is always challenging and frustrating due to poor response to the routinely used interventions in most situations. Here, we present a case with dissociative convulsions in order to catch the eye of the clinicians and researchers on the recognition of clinical manifestation and exploration of therapeutic strategies.
文摘Objective: Current randomized clinical trial was conducted to compare the efficacy and side effects of dissociative conscious sedation and conscious sedation in patients under bronchoscopy. Methods: In this randomized clinical trial, 110 patients scheduled for Fiberoptic Bronchoscopy in a training hospital in 2012 were enrolled and randomly assigned to receive either SC ketamine plus IV fentanyl (dissociative conscious sedation) or placebo plus IV fentanyl (conscious sedation) and the efficacy and side effects were assessed and compared. Results: There was significant difference between systolic and diastolic blood pressure and heart rate in two groups and more stability was shown in dissociative conscious sedation group (P < 0.05). Also the incidence of cough, the need to extra dose of fentanyl and recall showed less frequency in dissociative conscious sedation group (P < 0.05). Conclusions: Totally, according to the obtained results, it may be concluded that Subcutaneous Dissociative Conscious Sedation (sDCS) in comparison to Conscious Sedation is significantly more efficient accompanied by less side effects in fiberoptic bronchoscopy and using this method is recommended. Implication of the Manuscript: The study was designed in order to evaluate the efficacy of subcutaneous Dissociative Conscious Sedation (sDCS) Method in fiberoptic bronchoscopy.
文摘Purpose: Anesthesia and airway management for mediastinal masses are challenging and are accompanied by mortality and morbidity. Avoiding the loss of airway muscular tone in mediastinal masses has been confirmed necessary to avoid airway collapse. Sufficient spontaneous ventilation is of paramount importance in order to reduce the rate of mortality and morbidity. Various anesthetics and anesthesia techniques have been used for maintaining spontaneous ventilation and patent airway. In this report, a successful double lumen endobronchial intubation using “subcutaneous dissociative conscious sedation” as a novel method in the management of compromised airway (a case of a mediastinal mass) is presented. Clinical features: A 42 year- old, 62 Kg man was presented for an open biopsy of a middle mediastinal mass. The patient had a history of chest pain, dyspnea, cough, fever and sweats for 2 months. Regarding to the life threatening nature of mediastinal masses resulting from unpredictable events of airway obstruction and the reported cases of deaths after induction of anesthesia in patients with mediastinal masses and regarding to the importance of not losing muscular tone and keeping airway tone intact in patients with mediastinal masses” subcutaneous Dissociative Conscious Sedation (a novel method of anesthesia)”was selected in order to guarantee the safety of the patient and keep the airway secure. Conclusion: Owing to the characteristics of the “subcutaneous dissociative conscious sedation” this method is suggested as an appropriate substitute to general anesthesia for Endobronchial Double Lumen Intubation in mediastinal masses and compromised airway.
基金Financial support by the National Natural Science Foundation of China (29833060 29903009+2 种基金 20073012) and Visiting Scholar Foundation in State Key Labs of Ministry of Education of China is gratefully acknowledged.
文摘In situ Raman spectroscopic and voltammetric studies indicate that dissociative adsorption of methanol on the rough platinum electrode occurs in the hydrogen ad/desorption potential range, and the dissociative extent depends on the initial potential of the electrode before contacting methanol, in addition to the contacting time. As the dissociative product, carbon monoxide competes the site of strongly bound hydrogen preferentially, and shifts the ad/desorption potentials of weakly bound hydrogen towards more positive ones gradually with the increase of CO coverage. Whereas, formaldehyde dissociates more easily by far and completely suppresses H-adsorption. The confocal Raman spectroscopy developed on transition metals shows some intriguing advantages in investigating electrocatalytic oxidation of small organic molecules.
文摘The foreign accent syndrome(FAS) is a rare speech disorder, characterised by the appearance of a new accent, different from the speaker's native language and perceived as foreign by others. In the majority of patients, FAS is secondary to focal brain damage caused by stroke or other neurological disorders. Infrequently, FAS has been reported in association with psychiatric disorders, including dissociative or conversion disorders. The case of a young woman with recurrent episodes of speaking with a foreign accent is described. Repeated neurological examinations, imaging and electroencephalography did not reveal any brain abnormality. However, there was a history of a difficult childhood, alcohol dependence in the father, parental discord, alleged sexual abuse in the past, interpersonal difficulties and parental death. Episodes were precipitated by stressful life circumstances and resolved spontaneously, or with supportive treatment. She had additional "suspect" symptoms such as non-epileptic seizures, aphonia and motor paralysis. All these features indicated that a dissociative disorder was involved in the genesis of her FAS. The influence of external factors such as the media was unclear. Generally biological factors have been implicated in the onset of FAS, but the presentation in this young woman suggests that psychological factors such as personality, trauma, stressful life events and psychiatric disorder; familial factors such as parental discord and parental death and family conflicts; and, social factors such the possible influence of the media may also be involved in the production of foreign accents by patients.
文摘Despite outstanding improvements in anesthesia techniques and anesthetics, difficult airway is still a dilemma and is accompanied by morbidity and mortality. The aim of this study is to compare the feasibility of endotracheal intubation with the traditional method of general anesthesia by using muscle relaxants, and “sDCS” (Subcutaneous Dissociative Conscious Sedation) which has been recently reported as an efficient method of anesthesia with the capability of maintaining spontaneous ventilation and providing an appropriate situation for larynxgoscopy and endotracheal intubation. Material and Methods: This randomized clinical trial was conducted on 100 patients who were scheduled for elective laparotomy. Patients were randomly divided into two groups: group A and group B. In group A, patients underwent general anesthesia with thiopental sodium and relaxant. In group B, patients underwent “subcutaneous Dissociative Conscious Sedation” and received low dose subcutaneous ketamine and intravenous narcotic with no relaxant. The feasibility of direct laryngoscopy and tracheal intubation, hemodynamic changes, desaturation (SpO2 < 90%), patient cooperation, patient comfort, hallucination, nausea and vomiting, nystagmus and salivation were evaluated in two groups. Adverse events including apnea and need for positive pressure mask ventilation, additional dose of fentanyl were recorded in group B. The anesthesiologist who performed the procedure was asked about the patient calmness and cooperation during the procedure and the feasibility of laryngoscopy and tracheal intubation. The incidence of nausea and vomiting in post-operative care unit was recorded too. Results: Hemodynamic variables were comparable in two groups. No event of irreversible respiratory depression, desaturation, need for positive pressure ventilation and hallucination was observed in group B. All patients were cooperative and obedient during the laryngoscopy and tracheal intubation. The incidence of nausea was not statistically significant. The anesthesiologist was satisfied by the quality of patient’s cooperation for laryngoscopy in both groups. Conclusion: Subcutaneous dissociative conscious sedation is comparable with general anesthesia to provide desirable situation for laryngoscopy and tracheal intubation.
文摘Background: Dissociation may be defined as a psychopathological process in which an individual’s psyche splits into two or more parts. The division of personality is a key element in trauma, especially if the patient is not able to cope with it. At least one part of personality may be relatively able to understand and function in the objective reality, whilst other part(s) of the psyche may be more or less disorganized, dysfunctional and less able to understand the truth. Methods: literature review;conceptualization of dissociation, dissociative disorders and partial psychosis from medical and philosophical perspective. Conclusion: The core of dissociation and dissociative disorders is usually psychological trauma, especially emotional trauma, although some individuals may experience dissociation without any obvious cause or trigger. Carefully designed trauma-focused psychotherapy and psychosocial support are considered and must be further studied as the cornerstone of multidisciplinary approach in the treatment of dissociative disorders. Dissociative identity disorder in its severe form may resemble characteristics of partial psychosis. Some patients suffering from partial psychosis have narcissistic personality traits, such as shamelessness, magical thinking, arrogance, envy, entitlement, exploitation and bad boundaries, and therefore, developing healthy self-love, which is based on healthy self-criticism, realistic thinking, humility, gratefulness, democratic behavior, altruism and good boundaries, might be helpful for these patients.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10904004,10604010,60776063,50471070 and 50644041)
文摘Using first-principles calculations, we systematically study the potential energy surfaces and dissociation processes of the hydrogen molecule on the Mg(0001) surface. It is found that during the dissociative adsorption process with the minimum energy barrier, the hydrogen molecule first orients perpendicularly, and then rotates tobecome parallel to the surface. It is also found that the orientation of the hydrogen molecule in the transition state is neither perpendicular nor parallel to the surface. Most importantly we find that the rotation causes a reduction of the calculated dissociation energy barrier for the hydrogen molecule. The underlying electronic mechanism for the rotation of the hydrogen molecule is also discussed in the paper.
文摘Borderline personality disorder, conversion disorder and obsessive compulsive disorder frequently have dissociative symptoms. The literature has demonstrated that the level of dissociation might be correlated with the severity of obsessive compulsive disorder(OCD) and that those not responding to treatment had high dissociative symptoms. The structured clinical interview for DSM-IV dissociative disorders, dissociation questionnaire, somatoform dissociation questionnaire and dissociative experiences scale can be used for screening dissociative symptoms and detecting dissociative disorders in patients with OCD. However, a history of neglect and abuse during childhood is linked to a risk factor in the pathogenesis of dissociative psychopathology in adults. The childhood trauma questionnaire-53 and childhood trauma questionnaire-40 can be used for this purpose. Clinicians should not fail to notice the hidden dissociative symptoms and childhood traumatic experiences in OCD cases with severe symptoms that are resistant to treatment. Symptom screening and diagnostic tools used for this purpose should be known. Knowing how to treat these pathologies in patients who are diagnosed with OCD can be crucial.
基金Supported by the National Natural Science Foundation of China (11765005, 12042511)the Fund of Science and Technology Department of Guizhou Province([2019]5653)+2 种基金Fund of Education Department of Guizhou Province (KY[2021]131)the National Key Research and Development Program of China (2018YFE0104700,CCNU18ZDPY04)the fund of China Postdoctoral Science Foundation (2018M633414)
文摘We extend the hotspot model to include the virtuality dependence and use it to study the exclusive and dissociative J/Ψ production combined with the dipole amplitude in the target rapidity representation.We determined that virtuality takes effect on a number of hotspots,thus providing a better description of the J/Ψ production data at HERA.The collinear improved Balitsky-Kovchegove equation in the target rapidity representation is numerically solved and used to fit the J/Ψ experimental data with a series of hotspot sizes.We infer that virtuality significantly influences the number and size of hotspots.The expression χ^(2)/d.o.f=1.0183 resulting from the fit with the collinear improved dipole amplitude in the target rapidity representation is more reasonable than the correspondingχ^(2)/d.o.f=1.3995 originating from the leading order fit,which indicates that the collinear improved evolution equation in the target rapidity representation can provide a relatively good depiction of the exclusive and dissociative HERA data.
基金supported by the National Natural Science Foundation of China(21133006,21273104,91221301 and 91021010)the Ministry of Science and Technology(2013CB834601)
文摘Much progress has been achieved for both experimental and theoretical studies on the dissociative chemisorption of molecules on surfaces.Quantum state-resolved experimental data has provided unprecedented details for these fundamental steps in heterogeneous catalysis,while the quantitative dynamics is still not fully understood in theory.An in-depth understanding of experimental observations relies on accurate dynamical calculations,in which the potential energy surface and adequate quantum mechanical implementation are desired.This article summarizes the current methodologies on the construction of potential energy surfaces and the quantum mechanical treatments,some of which are promising for future applications.The challenges in this field are also addressed.
基金Project supported by the National Natural Science Foundation of China
文摘I. INTRODUCTION The chemisorption characteristics and reactivity near the ledge on the stepped surface as a defect on solid surface are worth noticing. In many cases, defects on metal surface not only control the adsoprtion rate of the gas molecule, but also have an impotant influence on the formation of a veriety of catalysates. For example, studying the catalytic oxidation
基金Supported by the National Natural Science Foundation of China (Grant Nos. 20833005 & 20873113)
文摘In the present paper we study the kinetics of dissociative adsorption of formic acid on the electrode of tetrahexahedral platinum nanocrystals (THH Pt NCs). In situ FTIR spectroscopic results demonstrate that HCOOH can be oxidized to CO2 at a low potential (-0.2 V(SCE)) on the THH Pt NCs electrode, and the chemical bonds inside formic acid molecule are broken to form adsorbed COL species. The kinetics of the dissociative adsorption of HCOOH was quantitatively investigated by employing programmed potential step technique. It has been determined that, in 5 × 10-3 mol·L-1 HCOOH + 0.1 mol·L-1 H2SO4 solution, the maximal value of the average rate (υamax) of dissociative adsorption of HCOOH on a commercial Pt/C catalyst electrode is 8.58 × 10-10 mol·cm-2·s-1, while on the THH Pt NCs the υamax is 1.5 times larger than the υamax measured on Pt/C and reaches 13.19 × 10-10 mol·cm-2·s-1. The results have revealed that the reactivity of the THH Pt NCs is much higher than that of the Pt/C catalysts.
基金Project supported by the National Natural Science Foundation of china.
文摘Ⅰ. INTRODUCTIONSome experiments showed that after forming graphite monolayer, the catalytic activites of some metal catalysts were reduced and lost. But mechanism of this process is still poorly understood. On the other hand, the reaction of hydrogengraphite system plays an important role in the field of exploiting and the use of energy source. Therefore, this system has attracted attention in further studying the kinetics of its reaction. Demidovish et al. studied EPR on the dissociative adsorption of H<sub>2</sub> on graphite surfacet. Dihydrogen recombination, being an inverse