Design of High-Remanence Nd-Fe-B Hot-Pressed Magnets by Manipulating Coercivity of Hydrogenation-Disproportionation-Desorption-Recombination Treated Anisotropic Precursors.

We propose a method of manipulating the coercivity of anisotropic hydrogenation-disproportionation-desorption-recombination (HDDR) powders to fabricate high-remanence and fine-grained Nd-Fe-B magnets using only hot-pressing without a subsequent hot-deformation process. By reducing the Nd content of anisotropic HDDR precursors such that their coercivity (Hcj) is lowered, the c-axis of each HDDR particle is well-aligned parallel to the direction of the applied magnetic field during the magnetic alignment step. This is because the magnetic repulsive force between adjacent particles, determined by their remanent magnetization, decreases as a result of the low coercivity of each particle. Therefore, after hot-pressing the low-Hcj HDDR powders, a significantly higher remanence (11.2 kG) is achieved in the bulk than that achieved by hot-pressing the high-Hcj HDDR powders (8.2 kG). It is clearly confirmed by the large-scale electron backscatter diffraction (EBSD) analysis that the alignment of the c-axis of each anisotropic HDDR particle in the bulk is improved when low-Hcj HDDR powders are used to fabricate hot-pressed magnets. This coercivity manipulation of HDDR powders can be a helpful method to expand the use of HDDR powders in fabricating anisotropic Nd-Fe-B bulk magnets.

Prevalence and Comorbidities of Adult Attention-deficit/hyperactivity Disorder in a Community Sample from Korea.

Objective: : Attention-deficit/hyperactivity disorder (ADHD) is prevalent in adults, and psychiatric comorbidities are common in adults with ADHD. We aimed to examine the prevalence of adult ADHD with several common psychiatric conditions in a community sample in Korea and the association between adult ADHD and risk of psychiatric comorbidities. Methods: : This study used a cross-sectional survey design. We provided supplementary and optional self-report questionnaires, including the Korean version of the World Health Organization Adult ADHD Self-Report Scale (ASRS) short screening scale, Patient Health Questionnaire-9 for screening for depression, Alcohol Use Disorders Identification Test alcohol consumption questions, and the Korean version of the Mood Disorders Questionnaire, to Korean adults who visited one of six centers of a large private healthcare company for the National General Health Examination. Results: : A total of 17,799 subjects included in this study, and 430 (2.4%) were positive on the ASRS screen. ADHD was significantly associated with the 19-30-year-old age group (odds ratio [OR] = 3.938), lower income (OR = 1.298), depression (OR = 11.563), and bipolar disorder (OR = 3.162). Conclusion: : Adult ADHD was highly associated with depression and bipolar disorder, suggesting that clinicians should carefully evaluate and treat such psychiatric disorders in adults with ADHD symptoms.

Conformationally Restricted Glycopeptide Backbone Inhibits Gas-Phase H/D Scrambling between Glycan and Peptide Moieties.

Protein glycosylation is a common post-translational modification on extracellular proteins. The conformational dynamics of several glycoproteins have been characterized by hydrogen/deuterium exchange mass spectrometry (HDX-MS). However, it is, in most cases, not possible to extract information about glycan conformation and dynamics due to the general difficulty of separating the deuterium content of the glycan from that of the peptide (in particular, for O-linked glycans). Here, we investigate whether the fragmentation of protonated glycopeptides by collision-induced dissociation (CID) can be used to determine the solution-specific deuterium content of the glycan. Central to this concept is that glycopeptides can undergo a facile loss of glycans upon CID, thereby allowing for the determination of their masses. However, an essential prerequisite is that hydrogen and deuterium (H/D) scrambling can be kept in check. Therefore, we have measured the degree of scrambling upon glycosidic bond cleavage in glycopeptides that differ in the conformational flexibility of their backbone and glycosylation pattern. Our results show that complete scrambling precedes the glycosidic bond cleavage in normal glycopeptides derived from a glycoprotein; i.e., all labile hydrogens have undergone positional randomization prior to loss of the glycan. In contrast, the glycosidic bond cleavage occurs without any scrambling in the glycopeptide antibiotic vancomycin, reflecting that the glycan cannot interact with the peptide moiety due to a conformationally restricted backbone as revealed by molecular dynamics simulations. Scrambling is also inhibited, albeit to a lesser degree, in the conformationally restricted glycopeptides ristocetin and its pseudoaglycone, demonstrating that scrambling depends on an intricate interplay between the flexibility and proximity of the glycan and the peptide backbone.

The Korean Medication Algorithm Project for Depressive Disorder (KMAP-DD): Changes in Preferred Treatment Strategies and Medications over 20 Years and Five Editions.

BACKGROUND: The Korean Medication Algorithm Project for Depressive Disorder (KMAP-DD) is an expert consensus guideline for depressive disorder created in 2002, and since then, four revisions (2006, 2012, 2017, 2021) have been published. In this study, changes in the content of the KMAP-DD survey and recommendations for each period were examined. METHODS: The development process of the KMAP-DD was composed of two stages. First, opinions from experts with abundant clinical experience were gathered through surveys. Next, a final guideline was prepared through discussion within the working committee regarding the suitability of the results with reference to recent clinical studies or other guidelines. RESULTS: In mild depressive symptoms, antidepressant (AD) monotherapy was preferred, but when severe depression or when psychotic features were present, a combination of AD and atypical antipsychotics (AD + AAP) was preferred. AD monotherapy was preferred in most clinical subtypes. AD monotherapy was preferred for mild depressive symptoms, and AD + AAP was preferred for severe depression and depression with psychotic features in children, adolescents, and the elderly. CONCLUSIONS: This study identified the changes in the KMAP-DD treatment strategies and drug preferences in each period over the past 20 years. This work is expected to aid clinicians in establishing effective treatment strategies.

Korean Medication Algorithm Project for Bipolar Disorder 2022: Comparisons with Other Treatment Guidelines.

The objective of this study was to compare recommendations of the Korean Medication Algorithm Project for Bipolar Disorder 2022 (KMAP-BP 2022) with other recently published guidelines for treating bipolar disorder. We reviewed a total of six recently published global treatment guidelines and compared treatment recommendation of the KMAP-BP 2022 with those of other guidelines. For initial treatment of mania, there were no significant differences across treatment guidelines. All guidelines recommended mood stabilizer (MS) or atypical antipsychotic (AAP) monotherapy or a combination of an MS with an AAP as a first-line treatment strategy in a same degree for mania. However, the KMAP-BP 2022 recommended MS + AAP combination therapy for psychotic mania, mixed mania and psychotic depression as treatment of choice. Aripiprazole, quetiapine and olanzapine were the first-line AAPs for nearly all phases of bipolar disorder across guidelines. Some guideline suggested olanzapine is a second-line options during maintenance treatment, related to concern about long-term tolerability. Most guidelines advocated newer AAPs (asenapine, cariprazine, long-acting injectable risperidone, and aripiprazole once monthly) as first-line treatment options for all phases while lamotrigine was recommended for depressive and maintenance phases. Lithium and valproic acid were commonly used as MSs in all phases of bipolar disorder. KMAP-BP 2022 guidelines were similar to other guidelines, reflecting current changes in prescription patterns for bipolar disorder based on accumulated research data. Strong preference for combination therapy was characteristic of KMAP-BP 2022, predominantly in the treatment of psychotic mania, mixed mania and psychotic depression.

Psychometric Properties of the Korean Version of Functioning Assessment Short Test in Bipolar Disorder.

Objective: The Functioning Assessment Short Test (FAST) is a relatively specific test for bipolar disorders designed to assess the main functioning problems experienced by patients. This brief instrument includes 24 items assessing impairment or disability in 6 domains of functioning: autonomy, occupational functioning, cognitive functioning, financial issues, interpersonal relationships, and leisure time. It has already been translated into standardized versions in several languages. The aim of this study is to measure the validity and reliability of the Korean version of FAST (K-FAST). Methods: A total of 209 bipolar disorder patients were recruited from 14 centers in Korea. K-FAST, Young Mania Rating Scale (YMRS), Bipolar Depression Rating Scale (BDRS), Global Assessment of Functioning (GAF) and the World Health Organization Quality of Life Assessment Instrument Brief Form (WHOQOL-BREF) were administered, and psychometric analysis of the K-FAST was conducted. Results: The internal consistency (Cronbach's alpha) of the K-FAST was 0.95. Test-retest reliability analysis showed a strong correlation between the two measures assessed at a 1-week interval (ICC = 0.97; p < 0.001). The K-FAST exhibited significant correlations with GAF (r = -0.771), WHOQOL-BREF (r = -0.326), YMRS (r = 0.509) and BDRS (r = 0.598). A strong negative correlation with GAF pointed to a reasonable degree of concurrent validity. Although the exploratory factor analysis showed four factors, the confirmatory factor analysis of questionnaires had a good fit for a six factors model (CFI = 0.925; TLI = 0.912; RMSEA = 0.078). Conclusion: The K-FAST has good psychometric properties, good internal consistency, and can be applicable and acceptable to the Korean context.

Effects of liraglutide on depressive behavior in a mouse depression model and cognition in the probe trial of Morris water maze test.

BACKGROUND: We investigated the effects of liraglutide, a glucagon-like peptide-1 (GLP-1) agonist, on a depression-like phenotype in mice exposed to chronic unpredictable stress (CUS). Learning and memory were also assessed using the Morris water maze (MWM) test. METHODS: Liraglutide (0.3 mg/kg/day for 21 days) was administered to mice with or without exposure to CUS. After 21 days of CUS, the forced swim test (FST) was performed to assess its antidepressant effect. To evaluate cognitive function, liraglutide was administered to mice under stress-free conditions for 21 days, and then the MWM test was performed on 6 consecutive days. RESULTS: Chronic liraglutide treatment reduced FST immobility in mice with and without CUS. In the probe trial of the Morris water maze test, the search error rate was reduced and the time spent and path length in the target quadrant and the number of platform crossings were increased. LIMITATION: Additional animal model experiments and molecular level studies are needed to support the results obtained in this study. CONCLUSIONS: Liraglutide appears to exert antidepressant effects and could improve cognitive function. Based on these results, GLP-1 agonists could have potential as novel antidepressants.

Korean Medication Algorithm Project for Bipolar Disorder 2022, Fifth Revision: An Executive Summary.

Objective: We revised the Korean Medication Algorithm Project for Bipolar Disorder (KMAP-BP), first published in 2002 and revised in 2006, 2010, 2014, and 2018, to reflect recent progress in the treatment of bipolar disorder. Methods: The questionnaires consisted of 56 items for adult patients and 7 items for child/adolescent patients, and were used to obtain the consensus of experts regarding pharmacological treatment strategies for various phases of bipolar disorder. The review committee included 87 Korean psychiatrists and 40 child and adolescent psychiatry experts. Results: For treatment of manic episodes, a combination of a mood stabilizer (MS) and atypical antipsychotics (AAP), or monotherapy with MS or AAP were recommended as first-line treatments. Combinations of MS and AAP, or AAP and lamotrigine (LMT) were recommended as first-line treatments for depressive episodes regardless of the severity. Monotherapy with MS, AAP, or LMT were also first-line treatments for mild to moderate depressive episodes. For mixed features, a combination of MS and AAP, or monotherapy with AAP or MS were recommended as first-line treatments, and a combination of AAP and LMT, or MS and LMT were the first-line treatments for depressive mixed state. Conclusion: The recommendations of the KMAP-BP 2022 have changed from the previous version, to reflect the evolution of the social culture and healthcare system in Korea and recent evidence regarding pharmacotherapy of bipolar disorder. The KMAP-BP 2022 provides clinicians with a wealth of information regarding appropriate strategies to treat patients with bipolar disorder.

Facile synthesis of epsilon iron oxides via spray drying for millimeter-wave absorption.

A simple, scalable spray drying method was developed for high-yield epsilon iron oxide (ε-Fe2O3) synthesis. The ε-Fe2O3 particle size can be tailored by varying the annealing temperature and molar ratio of Fe/Si, producing a high-purity ε-phase. This strategy also enables ferromagnetic resonance tuning, making it potentially usable in millimeter-wave absorbers.

Effects of Chronic LY341495 on Hippocampal mTORC1 Signaling in Mice with Chronic Unpredictable Stress-Induced Depression.

In several rodent models, acute administration of the metabotropic glutamate 2/3 (mGlu2/3) receptor antagonist LY341495 induced antidepressant-like effects via a mechanism of action similar to that of ketamine. However, the effects of chronic mGlu2/3 antagonism have not yet been explored. Therefore, we investigated the effects of chronic LY341495 treatment on the mechanistic target of rapamycin complex 1 (mTORC1) signaling and the levels of synaptic proteins in mice subjected to chronic unpredictable stress (CUS). LY341495 (1 mg/kg) was administered daily for 4 weeks to mice with and without CUS exposure. After the final treatment, the forced swimming test (FST) was used to assess antidepressant-like effects. The hippocampal levels of mTORC1-related proteins were derived by Western blotting. Chronic LY341495 treatment reversed the CUS-induced behavioral effects of FST. CUS significantly reduced the phosphorylation of mTORC1 and downstream effectors [eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP-1) and small ribosomal protein 6 (S6)], as well as the expression of synaptic proteins postsynaptic density-95 (PSD-95) and AMPA receptor subunit GluR1 (GluA1) in the hippocampus. However, chronic LY341495 treatment rescued these deficits. Our results suggest that the activation of hippocampal mTORC1 signaling is related to the antidepressant effect of chronic LY341495 treatment in an animal model of CUS-induced depression.

Differential expression of gene co-expression networks related to the mTOR signaling pathway in bipolar disorder.

Bipolar disorder (BPD) is a severe mental illness characterized by episodes of depression and mania. To investigate the molecular mechanisms underlying the pathophysiology of bipolar disorder, we performed transcriptome studies using RNA-seq data from the prefrontal cortex (PFC) of individuals with BPD and matched controls, as well as data from cell culture and animal model studies. We found 879 differentially expressed genes that were also replicated in an independent cohort of post-mortem samples. Genes involving the mechanistic target of rapamycine (mTOR) pathway were down-regulated, while genes interrelated with the mTOR pathway such as Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway were up-regulated. Gene co-expression network analyses identified a module related to the mTOR pathway that was up-regulated in BPD and also enriched for markers of endothelial cells. We also found a down-regulated co-expression module enriched for genes involved in mTOR signalling and in mTOR related pathways and enriched with neuronal markers. The mTOR related modules were also replicated in the independent cohort of samples. To investigate whether the expression of the modules related to mTOR signalling pathway could be differentially regulated in different cell types we performed comparative network analyses in experimental models. We found both up-regulated modules in the PFC significantly overlapped with an up-regulated module in the brain endothelial cells from mice treated with lipopolysaccharides (LPS) and mTOR related pathways such as JAK-STAT, PI3K-Akt and ribosome were enriched in the common genes. In addition, the down-regulated module in the PFC significantly overlapped with a down-regulated module from neurons treated with the mTOR inhibitor, Torin1 and mTOR signalling, autophagy, and synaptic vesicle cycles were significantly enriched in the common genes. These results suggest that co-expression networks related to mTOR signalling pathways may be up- or down-regulated in different cell types in the PFC of BPD. These results provide novel insights into the molecular mechanisms underlying the pathophysiology of BPD.

Neuromolecular Etiology of Bipolar Disorder: Possible Therapeutic Targets of Mood Stabilizers.

Bipolar disorder is a mental illness that causes extreme mood swings and has a chronic course. However, the mechanism by which mood episodes with completely opposite characteristics appear repeatedly, or a mixture of symptoms appears, in patients with bipolar disorder remains unknown. Therefore, mood stabilizers are indicated only for single mood episodes, such as manic episodes and depressive episodes, and no true mood-stabilizing drugs effective for treating both manic and depressive episodes currently exist. Therefore, in this review, therapeutic targets that facilitate the development of mood stabilizers were examined by reviewing the current understanding of the neuromolecular etiology of bipolar disorder.

The Korean Medication Algorithm Project for Depressive Disorder 2021: Comparisons with Other Treatment Guidelines.

The Korean Medication Algorithm Project for Depressive Disorder (KMAP-DD) first was published in 2002, and has been revised four times, in 2006, 2012, 2017, and 2021. In this review, we compared recommendations from the recently revised KMAP-DD 2021 to four global clinical practice guidelines (CPGs) for depression published after 2010. The recommendations from the KMAP-DD 2021 were similar to those from other CPGs, although there were some differences. The KMAP-DD 2021 reflected social culture and the healthcare system in Korea and recent evidence about pharmacotherapy for depression, as did other recently published evidence-based guidelines. Despite some intrinsic limitations as an expert consensus-based guideline, the KMAP-DD 2021 can be helpful for Korean psychiatrists making decisions in clinical settings by complementing previously published evidence-based guidelines, especially for some clinical situations lacking evidence from rigorously designed clinical trials.

Korean Medication Algorithm for Depressive Disorder 2021, Fourth Revision: An Executive Summary.

OBJECTIVE: In the 19 years since the Korean College of Neuropsychopharmacology and the Korean Society for Affective Disorders developed the Korean Medication Algorithm Project for Depressive Disorder (KMAP-DD) in 2002, four revisions have been conducted. METHODS: To increase survey efficiency in this revision, to cover the general clinical practice, and to compare the results with previous KMAP-DD series, the overall structure of the questionnaire was maintained. The six sections of the questionnaire were as follows: 1) pharmacological treatment strategies for major depressive disorder (MDD) with/without psychotic features; 2) pharmacological treatment strategies for persistent depressive disorder and other depressive disorder subtypes; 3) consensus for treatment-resistant depression; 4) the choice of an antidepressant in the context of safety, adverse effects, and comorbid physical illnesses; 5) treatment strategies for special populations (children/adolescents, elderly, and women); and 6) non-pharmacological biological therapies. Recommended first-, second-, and third-line strategies were derived statistically. RESULTS: There has been little change in the four years since KMAP-DD 2017 due to the lack of newly introduced drug or treatment strategies. However, shortened waiting time between the initial and subsequent treatments, increased preference for atypical antipsychotics (AAPs), especially aripiprazole, and combination strategies with AAPs yield an active and somewhat aggressive treatment trend in Korea. CONCLUSION: We expect KMAP-DD to provide clinicians with useful information about the specific strategies and medications appropriate for treating patients with MDD by bridging the gap between clinical real practice and the evidence-based world.

The structural and magnetic properties of BaFe12O19 nanoparticles: effect of residual sodium ions.

We studied the structural and magnetic properties of BaFe12O19 (BaM) nanoparticles synthesized by a co-precipitation route based on a modified citrate process. The lattice contraction of co-precipitated BaM nanoparticles is detected after prolonged sintering at 900 °C. In addition, investigation with X-ray photoelectron spectroscopy (XPS) provides evidence of a highly enhanced population of oxygen vacancies. The lattice distortion and formation of oxygen vacancies are attributed to a direct result of substitutional incorporation of smaller Na ions into Ba2+ sites in the lattice of BaM during prolonged annealing. The aliovalent impurities are assumed to be originated from NaOH which has been incorporated as a pH modifier. Magnon scattering is detected at 1640 cm-1 in the low temperature Raman spectra of BaM. Minimization of the magnon peak is also identified after prolonged annealing, which indicates oxygen vacancy-induced collapse of strong anti-ferromagnetic interaction between Fe3+ ions in the bipyramidal sites and the octahedral sites in BaM nanoparticles. As a result, the saturation magnetization (Ms) of BaM nanoparticles is enhanced by the onset of local ferromagnetic interaction induced by the collapse of antiferromagnetic interaction between oppositely aligned spins. In this study, we re-investigated the evolution of structural and magnetic properties with prolonged annealing of BaM nanoparticles and the effects of residual Na ions are also discussed.

Early life stress induces age-dependent epigenetic changes in p11 gene expression in male mice.

Early life stress (ELS) causes long-lasting changes in gene expression through epigenetic mechanisms. However, little is known about the effects of ELS in adulthood, specifically across different age groups. In this study, the epigenetic modifications of p11 expression in adult mice subjected to ELS were investigated in different stages of adulthood. Pups experienced maternal separation (MS) for 3 h daily from postnatal day 1 to 21. At young and middle adulthood, behavioral test, hippocampal p11 expression levels, and levels of histone acetylation and methylation and DNA methylation at the hippocampal p11 promoter were measured. Middle-aged, but not young adult, MS mice exhibited increased immobility time in the forced swimming test. Concurrent with reduced hippocampal p11 levels, mice in both age groups showed a decrease in histone acetylation (AcH3) and permissive histone methylation (H3K4me3) at the p11 promoter, as well as an increase in repressive histone methylation (H3K27me3). Moreover, our results showed that the expression, AcH3 and H3Kme3 levels of p11 gene in response to MS were reduced with age. DNA methylation analysis of the p11 promoter revealed increased CpG methylation in middle-aged MS mice only. The results highlight the age-dependent deleterious effects of ELS on the epigenetic modifications of p11 transcription.

Prevention and Management of Common Adverse Effects of Ketamine and Esketamine in Patients with Mood Disorders.

The emerging roles of ketamine and esketamine as effective rapid-acting antidepressants hold promise for patients suffering from treatment-resistant depression and/or major depressive disorder with suicidality. Practitioner familiarity with common tolerability/safety concerns along with pragmatic prevention and management strategies are needed to reduce patient burden and improve the acceptability and accessibility of these treatments. The most common treatment-emergent adverse events associated with ketamine/esketamine are dissociation, anxiety, nausea, increased blood pressure, and headache. The majority of side effects are mild, transient, dose dependent, and attenuate with subsequent treatments. Patient selection, baseline physical and psychiatric assessments, and an appropriate setting are critical first steps in the prevention and mitigation of adverse events. Patient education and supportive interventions play central roles in the prevention and management of select adverse events. Severe and/or clinically significant adverse effects may necessitate the judicious use of adjunctive medications. Moreover, practitioners must remain vigilant to the potential for abuse liability and long-term adverse events, for which there are insufficient data. This article succinctly reviews common treatment-emergent adverse events of ketamine and esketamine within the context of mood disorders, and provides practical suggestions for prevention and management at point-of-care.

The effect of intravenous ketamine on cognitive functions in adults with treatment-resistant major depressive or bipolar disorders: Results from the Canadian rapid treatment center of excellence (CRTCE).

Ketamine may exert pro-cognitive effects on select measures of cognition in adults with mood disorders. We evaluated the effectiveness of intravenous (IV) ketamine on cognition in 68 adult outpatients with treatment-resistant depression (TRD) at the Canadian Rapid Treatment Center of Excellence between July 3, 2018 and April 16, 2020 (NCT04209296). Eligibility criteria for the present retrospective study included: primary diagnosis of major depressive or bipolar disorder; currently depressed; and insufficient response to two or more prior treatments. Participants received four infusions of ketamine hydrochloride (0.5-0.75 mg/kg) over 1-2 weeks. We assessed objective and subjective measures of cognition before and after two infusions, i.e., Digit Symbol Substitution Test (DSST), Trail Making Test-B (TMT-B), Patient Deficits Questionnaire, 5-item (PDQ-5-D). Ketamine significantly improved DSST (effect size [ES]=0.60), TMT-B (ES=0.84), as well as PDQ-5-D scores (ES=0.63), indicative of a moderate-to-large effect size. Improvements in DSST and PDQ-5-D with ketamine were mediated by reductions in depressive symptoms, whereas improvements in TMT-B were independent of changes in depressive symptoms. Our results support the independent, rapid-onset, pro-cognitive effects with IV ketamine in adults with TRD. Larger, randomized, controlled trials with ketamine wherein cognition is the primary outcome measure in mood and non-mood disorder samples are warranted.

Synthesizing the Evidence for Ketamine and Esketamine in Treatment-Resistant Depression: An International Expert Opinion on the Available Evidence and Implementation.

Replicated international studies have underscored the human and societal costs associated with major depressive disorder. Despite the proven efficacy of monoamine-based antidepressants in major depression, the majority of treated individuals fail to achieve full syndromal and functional recovery with the index and subsequent pharmacological treatments. Ketamine and esketamine represent pharmacologically novel treatment avenues for adults with treatment-resistant depression. In addition to providing hope to affected persons, these agents represent the first non-monoaminergic agents with proven rapid-onset efficacy in major depressive disorder. Nevertheless, concerns remain about the safety and tolerability of ketamine and esketamine in mood disorders. Moreover, there is uncertainty about the appropriate position of these agents in treatment algorithms, their comparative effectiveness, and the appropriate setting, infrastructure, and personnel required for their competent and safe implementation. In this article, an international group of mood disorder experts provides a synthesis of the literature with respect to the efficacy, safety, and tolerability of ketamine and esketamine in adults with treatment-resistant depression. The authors also provide guidance for the implementation of these agents in clinical practice, with particular attention to practice parameters at point of care. Areas of consensus and future research vistas are discussed.