Quantum Critical Behavior of Entanglement in Lattice Bosons with Cavity-Mediated Long-Range Interactions.

We analyze the ground-state entanglement entropy of the extended Bose-Hubbard model with infinite-range interactions. This model describes the low-energy dynamics of ultracold bosons tightly bound to an optical lattice and dispersively coupled to a cavity mode. The competition between on-site repulsion and global cavity-induced interactions leads to a rich phase diagram, which exhibits superfluid, supersolid, and insulating (Mott and checkerboard) phases. We use a slave-boson treatment of harmonic quantum fluctuations around the mean-field solution and calculate the entanglement entropy across the phase transitions. At commensurate filling, the insulator-superfluid transition is signaled by a singularity in the area-law scaling coefficient of the entanglement entropy, which is similar to the one reported for the standard Bose-Hubbard model. Remarkably, at the continuous Z_{2} superfluid-to-supersolid transition we find a critical logarithmic term, regardless of the filling. This behavior originates from the appearance of a roton mode in the excitation and entanglement spectrum, becoming gapless at the critical point, and it is characteristic of collective models.

Mitochondrial complex II regulates a distinct oxygen sensing mechanism in monocytes.

Mutations in mitochondrial complex II (succinate dehydrogenase; SDH) genes predispose to paraganglioma tumors that show constitutive activation of hypoxia responses. We recently showed that SDHB mRNAs in hypoxic monocytes gain a stop codon mutation by APOBEC3A-mediated C-to-U RNA editing. Here, we test the hypothesis that inhibition of complex II facilitates hypoxic gene expression in monocytes using an integrative experimental approach. By RNA sequencing, we show that specific inhibition of complex II by atpenin A5 in normoxic conditions mimics hypoxia and induces hypoxic transcripts as well as APOBEC3A-mediated RNA editing in human monocytes. Myxothiazol, a complex III inhibitor, has similar effects in normoxic monocytes. Atpenin A5 partially inhibits oxygen consumption, and neither hypoxia nor atpenin A5 in normoxia robustly stabilizes hypoxia-inducible factor (HIF)-1α in primary monocytes. Several earlier studies in transformed cell lines suggested that normoxic stabilization of HIF-1α explains the persistent expression of hypoxic genes upon complex II inactivation. On the contrary, we find that atpenin A5 antagonizes the stabilization of HIF-1α and reduces hypoxic gene expression in transformed cell lines. Accordingly, compound germline heterozygosity of mouse Sdhb/Sdhc/Sdhd null alleles blunts chronic hypoxia-induced increases in hemoglobin levels, an adaptive response mainly regulated by HIF-2α. In contrast, atpenin A5 or myxothiazol does not reduce hypoxia-induced gene expression or RNA editing in monocytes. These results reveal a novel role for mitochondrial respiratory inhibition in induction of the hypoxic transcriptome in monocytes and suggest that inhibition of complex II activates a distinct hypoxia signaling pathway in a cell-type specific manner.

Transient overexpression of exogenous APOBEC3A causes C-to-U RNA editing of thousands of genes.

APOBEC3A cytidine deaminase induces site-specific C-to-U RNA editing of hundreds of genes in monocytes exposed to hypoxia and/or interferons and in pro-inflammatory macrophages. To examine the impact of APOBEC3A overexpression, we transiently expressed APOBEC3A in HEK293T cell line and performed RNA sequencing. APOBEC3A overexpression induces C-to-U editing at more than 4,200 sites in transcripts of 3,078 genes resulting in protein recoding of 1,110 genes. We validate recoding RNA editing of genes associated with breast cancer, hematologic neoplasms, amyotrophic lateral sclerosis, Alzheimer disease and primary pulmonary hypertension. These results highlight the fundamental impact of APOBEC3A overexpression on human transcriptome by widespread RNA editing.

SINE polymorphism reveals distinct strains of Entamoeba histolytica from North India.

Entamoeba histolytica is an intestinal parasite causing significant morbidity and mortality in the developing world. More tools are needed to understand the epidemiology and molecular pathogenesis of amebiasis. Virulence pattern of E. histolytica could be linked with the genotype of a strain. Several loci showing insertion polymorphism of retrotransposable short interspersed nuclear elements EhSINE1 and EhSINE2 have been reported among laboratory strains of E. histolytica. The present study was undertaken to validate this observation in clinical isolates from north India. Our results indicate that the Indian samples show a different propensity of SINE retention or loss at two of the polymorphic loci compared with non-Indian samples. Statistical analysis of different loci revealed Locus 17 of EhSINE1as a potential geographical marker for distinguishing Indian isolates from non Indian isolates.

Modulating TRAP-mediated transcription termination by AT during transcription of the leader region of the Bacillus subtilis trp operon.

An 11-subunit protein called trp RNA binding Attenuation Protein (TRAP) controls attenuation of the tryptophan biosynthetic (trpEDCFBA) operon in Bacillus subtilis. Tryptophan-activated TRAP binds to 11 (G/U)AG repeats in the 5' leader region of trp mRNAs, and downregulates expression of the operon by promoting transcription termination prior to the structural genes. Anti-TRAP (AT) is an antagonist that binds to tryptophan-activated TRAP and prevents TRAP from binding to RNA, thereby upregulating expression of the trp genes. AT forms trimers, and multiple trimers bind to a TRAP 11mer. It is not known how many trimers must bind to TRAP in order to interfere with RNA binding. Studies of isolated TRAP and AT showed that AT can prevent TRAP from binding to the trp leader RNA but cannot dissociate a pre-formed TRAP-RNA complex. Here, we show that AT can prevent TRAP-mediated termination of transcription by inducing dissociation of TRAP from the nascent RNA when it has bound to fewer than all 11 (G/U)AG repeats. The 5'-most region of the TRAP binding site in the nascent transcript is most susceptible to dissociation from TRAP. We also show that one AT trimer bound to TRAP 11mer reduces the affinity of TRAP for RNA and eliminates TRAP-mediated transcription termination in vitro.

Study to Evaluate the Pattern of Nodal Distribution in Papillary Thyroid Cancer.

Among the thyroid cancers, papillary thyroid cancer (PTC) is the most common with lymphatic metastasis. It has the propensity to spread to the level II-VI lymph nodes in a predictable manner. We evaluated the pattern of nodal distribution at different levels of neck in papillary thyroid cancer in this Observational Prospective study. Total 41 patients of PTC (Papillary thyroid cancer) were included in the study. 36 out of them were diagnosed as PTC by FNAC and underwent total thyroidectomy and central neck dissection, while 5 patients were histologically confirmed cases of PTC on previous hemithyroidectomy and underwent completion thyroidectomy and central neck dissection .Patients with T3/T4 stage or N1 underwent lateral neck dissection also. Clinicopathological factors such as age, sex, tumor stage, nodal metastasis and extracapsular invasion, were evaluated. Lymph node metastasis was noted in 21 patients (51.2%) and all these patients had central (level VI) lymph node involvement. Among 21 patients, pathological ipsilateral lateral neck metastasis was noted in 6 patients (28.57%) at level II, 10 patients (47.62%) at level III and 8 patients (38.10%) at level IV. Only 5 patients (23.81%) had metastasis at level V. Extracapsular invasion was observed in 10 (24.4%) patients. We concluded that patients with PTC show higher rates of metastasis at central neck (level VI) and are not easily detected on clinical examination or by USG due to low sensitivity but are sensitive and specific for lateral neck nodes in late stages . Thus, ipsilateral selective neck dissection should be considered with total thyroidectomy and central neck dissection in presence of clinically or radiologically evident lateral lymph nodes (preoperatively) and in T3, T4 stage (late stages) tumors.

A Prospective Study on Correlation of MERI (Middle Ear Risk Index) Score with Surgical Outcome of Tympano-mastoid Surgery in Patients of CSOM.

Chronic otits media (COM) is surgically treatable disease which includes complete removal of disease and improving hearing via ossicular reconstruction. Therefore, thorough assessment of the disease, ossicles and various factors causing it plays a major role in surgical outcome prediction. MERI (Middle ear risk index) is one such tool being used worldwide. Our aim was to evaluate the surgical outcome of tympanomastoid surgery using MERI and find out correlation between them as well as categorize cases into their severity score in a developing country. Observational prospective study conducted in a tertiary care center. 200 patients were included. After complete history and examination, they were given MERI scores and prediction of surgical outcome was done. Postoperatively it was compared with the real outcome of the surgery. Out of 200 patients, 71.5% had mild, 15.5% had moderate and 13% had severe MERI scores preoperatively. There was a success rate of 88.5% in graft uptake and the mean score of hearing benefit (A-B gain) among patients was 8.75 ± 8.82 dB postoperatively. MERI may be used as a prognostic indicator for predicting surgical outcome. Based on the MERI score, chances of surgical success and hearing benefit can be explained to the patient with certain limitations.

Efficacy of Sucralfate in Alleviating Post Tonsillectomy Symptoms and Morbidity: A Comparative Randomized Interventional Study.

Pain following tonsillectomy still remains the main concern of topic and it occurs along with sever ear pain and trismus until and unless the exposed and inflamed mucosa gets covered with the regenerated mucosa. To study the efficacy of sucralfate in alleviating postoperative pain and morbidity following tonsillectomy. Subjects included in our study were patients which were fulfilling criteria for tonsillectomy and were admitted under the Department of Otorhinolaryngology, SMS Medical College and Hospital, Jaipur from 1st July 2019 to 31st March 2020. 64 patients were evaluated and were randomly allocated into study and control group based on the administration of topical sucralfate. 64 patients who were admitted for tonsillectomy under the Department of Otorhinolaryngology, SMS Medical College and Hospital, Jaipur from 1st July 2019 to 31st March 2020 were included in study. Patients were evaluated and were randomly allocated into study and control group based on the administration of topical sucralfate. The incidence of throat pain and otalgia showed significant difference among both the group following postoperative day 2 onwards. On postoperative day 2, significant difference in trismus was also found. Effective alleviation of pain not only improves early dietary intake of the patients but also allays fear of apprehensive parents.

A Prospective Randomized Study to Compare Surgical Outcome Using Wet and Dry Temporalis Fascia Graft in Type I Tympanoplasty.

Temporalis fascia is being used as graft material for tympanic membrane repair for over six decades. Though cartilage with or without perichondrium is also being used for different situations, still temporalis fascia graft is being considered as an ideal graft for tympanoplasty. Earlier the dried temporalis fascia was used as a graft but now freshly taken wet temporalis fascia is increasingly being used as a more 'physiological/ live' graft. The present study was planned to compare the results of use of wet and dry temporalis fascia in chronic otitis media mucosal disease. The prospective study was conducted on 100 patients of chronic suppurative otitis media mucosal disease. Chronic ear survey questionnaire were filled to note the impact on quality of life. Otoscopic, oto-endoscopic and examination under microscope performed. Patients were allocated into two groups alternately. Freshly taken wet temporalis graft was used in group I whereas dry temporalis fascia was used in group II. Hearing evaluation by pure tone audiogram was done preoperatively and at 6th months post-operatively. Pre-operative and post-operative hearings in both the groups were compared. Air bone gap closures after surgery in between both the groups were compared to see for any statistical difference. We found similar graft uptake in both the groups after 6 months of surgery. The air bone gap closure in group I was 10.80 ± 5.74 and group II was 9.28 ± 4.81, there was no significant difference. However senior authors noted that in some of the cases in group I with fresh wet graft placement neo-tympanum formation was noticed early showing good circumferential leash of blood vessels all around signifying early vascularisation.

An Observational Study on Association of Clinical Outcome of Diphtheria Cases with Immunization Status: A Tertiary Care Hospital, Jaipur.

BACKGROUND: Diphtheria is an important vaccine preventable disease with varied outcome from mild to death. It was observed that the outcome also gets affected with status of immunization. The outcome is relatively milder in immunized children. OBJECTIVE: To find out the clinical presentation and outcome of diphtheria cases and its association with the immunization status. METHODS: A descriptive analysis of 64 diphtheria cases admitted from January 2019 to May 2020 at SMS hospital, a tertiary care referral hospital in Jaipur. RESULTS: Half of (51.56%, 33/60) patients were in the age group of 6-10 years. The peak load (48.44%) of diphtheria cases was seen in the monsoon season. Around 60% of the patients were fully immunized and around 10% partially immunized, every third case was un-immunized. The most common complication was neurological in 13 cases (20.31%), followed by cardiac complications in 11 cases (17.19%), and respiratory (7.81%). The proportion of complication was much lower (26.3%) in immunized cases as compare to partially immunized and un immunized. The proportion of myocarditis was significantly higher in un immunized cases (40%) than partially immunized (16.7%) and filly immunized group (5.3%). Similarly, Bronchopneumonia was also significantly higher (20%) in unimmunized. CONCLUSION: Our study depicted that there has been a shift of age above 5 years for diphtheria which suggests the need for the booster dose. Also high chances of complications are seen in unimmunized and partially immunized calling for public awareness regarding complete immunization.

A Study of Pulmonary Function Tests in Patients with Chronic Rhinosinusitis Following Endoscopic Sinus Surgery.

Chronic inflammatory disorders of the upper airways are extremely prevalent and they have a major impact on public health.To assess the change in pulmonary function tests in patients of chronic rhinosinusitis undergoing functional endoscopic sinus surgery pre operatively and post operatively.To evaluate the difference in mean of FEV1, FEV1%, FVC, FVC%, FEV1/FVC in patients of chronic rhinosinusitis undergoing functional endoscopic sinus surgery.Prospective observational study.From July 2019 to September 2020 in Department of ENT and Head & Neck surgery, SMS Medical College, Jaipur.There was a significant improvement in the mean FEV1, FEV1%, FVC, and FVC% values post-surgically (p < 0.05). In our study, there was also a significant improvement in the FEV1/FVC value at one month postoperatively, reflecting the effect of FESS on relieving the symptomatic lower airway obstruction.Our study concludes that following Functional Endoscopic Sinus Surgery there is significant improvement in pulmonary function tests reflecting the improvement of asymptomatic lower airway disease in cases of chronic rhinosinusitis.

Spectrum of Neurological Outcomes in Diphtheria: A Case Series.

Diphtheria is an acute infectious disease caused by the exotoxin produced by Corynebacterium diphtheriae, a gram positive bacteria. It has propensity to affect mainly cardiac muscle and nervous system. To study the percentage, spectrum of patients with various neurological complications and the pattern of recovery in followed up confirmed cases of diphtheria. Single centre prospective analysis of neurological complications in diphtheria patients from June 2019 to September 2020 at SMS Medical College and hospital,Jaipur. In this study, 60 cases were included. Immunised cases were 60% (36 out of 60 cases) whereas unimmunised constituted the rest 40% (24 out of 60 cases). Neurological complications were observed in 15% of the cases (9 out of 60). Isolated palatal palsy was the most common complication (4 out of 9 cases, 44.44%), succeeded by lower limb LMN palsies (2 out of 9 cases, 22.22%) with unilateral facial nerve palsy, bilateral abductor palsy and paralytic ileus constituting the rest (1 out of 9 cases each, 11.11% each). Onset of complications ranged from 10 to 36 days whereas recovery was complete and without any residual sequelae between 60 to 240 days. Our study concluded that neurological complications form a sizeable portion of post diptheritic complications and carries good prognosis, hence timely diagnosis and differentiation from other neuropathies is a pre requisite for rational management and contact tracing.

"An Observational Study on Association of Clinical Diagnosis of Diphtheria with Smear and Culture Test: A Tertiary Care Hospital, Jaipur".

Diphtheria is an acute infectious upper respiratory tract disease caused by toxigenic strains of Corynebacterium diphtheria and can lead to significant morbidity and mortality in all the age groups. Most of the time diagnosis of diphtheria is clinical. There may be a dirty white patch covering one or both tonsils on examination for which throat swabs are collected for Kleb's-Loeffler's Bacillus (KLB) by direct microscopy and for culture and sensitivity of the organism. To find out the association between clinical diagnosis of diphtheria with smear and culture positivity. 674 cases of Clinical diphtheria were admitted from June 2017 to September 2020 at a tertiary care hospital, Sawai Mansingh Hospital, Jaipur. throat, difficulty in swallowing and swelling in the neck. Out of 674 patients of clinical diphtheria, majority 610 cases (90.5%) were found to have both KLB smear and culture negative. 13 cases (1.9%) were found to have both KLB smear and culture positive. 19 cases (2.8%) were found to have KLB smear positive and culture negative and remaining 32 cases (4.8%) were found to have KLB smear negative and culture positive. Out of 19 patients of KLB smear positive,11 cases (3.5%) were found to have complications. Out of 32 culture positive patients,24 cases (7.7%) were found to have complications. Out of 13 patients of both KLB smear and culture positive,11 cases (3.5%) were found to have complications. Our study concluded that the negative report of KLB smear and culture does not rule out diphtheria and it is evident that percentage of complication is high in patients with either KLB smear or culture or both positive with respect to both being negative. The correlation is found to be significant (p < 0.001).

Fosfomycin versus Nitrofurantoin for the Treatment of Lower UTI in Outpatients.

Introduction Fosfomycin and nitrofurantoin are increasingly being prescribed in outpatients for the oral treatment of urinary tract infection (UTI). Although ample literature is available on the in vitro sensitivity pattern of fosfomycin and nitrofurantoin in UTI cases, clinical data are scant. Methodology Voided midstream urine, collected from patients ≥ 16 years of age of both genders with suspected sign and symptoms, was plated on cystine lactose electrolyte-deficient agar. Uropathogen was defined as an organism known to be associated with the signs and symptoms of UTI with > 10 5 colony forming units/mL of urine. Antimicrobial susceptibility testing was determined by Kirby-Bauer disc diffusion method. Further, for fosfomycin, agar dilution method was also performed. Results A total of 143 patients, 47 treated with fosfomycin and 96 with nitrofurantoin, were followed for clinical outcome. The most common isolated uropathogen was Escherichia coli . In vitro susceptibility rate of uropathogens against fosfomycin and nitrofurantoin was 99.3% and 81.2%, respectively. Overall, the clinical cure rate with fosfomycin and nitrofurantoin treatment groups was 80.85% and 90.06% respectively (not statistically significant). Conclusion Fosfomycin and nitrofurantoin showed good in vitro activity against uropathogens from lower UTI and can be used for empirical therapy in our area. Multiple confounding factors may have contributed to the discrepancy between in vitro susceptibility and clinical cure, which needs to be studied further.

RNA editing enzyme APOBEC3A promotes pro-inflammatory M1 macrophage polarization.

Pro-inflammatory M1 macrophage polarization is associated with microbicidal and antitumor responses. We recently described APOBEC3A-mediated cytosine-to-uracil (C > U) RNA editing during M1 polarization. However, the functional significance of this editing is unknown. Here we find that APOBEC3A-mediated cellular RNA editing can also be induced by influenza or Maraba virus infections in normal human macrophages, and by interferons in tumor-associated macrophages. Gene knockdown and RNA_Seq analyses show that APOBEC3A mediates C>U RNA editing of 209 exonic/UTR sites in 203 genes during M1 polarization. The highest level of nonsynonymous RNA editing alters a highly-conserved amino acid in THOC5, which encodes a nuclear mRNA export protein implicated in M-CSF-driven macrophage differentiation. Knockdown of APOBEC3A reduces IL6, IL23A and IL12B gene expression, CD86 surface protein expression, and TNF-α, IL-1ß and IL-6 cytokine secretion, and increases glycolysis. These results show a key role of APOBEC3A cytidine deaminase in transcriptomic and functional polarization of M1 macrophages.

Staphylococcus aureus including MRSA nasal carriage among hospital exposed and unexposed medical students.

INTRODUCTION: Staphylococcus aureus is one of the most common human pathogen causing a wide range of infections. It is estimated that S.aureus colonizes the anterior nares in approximately 31% of the general population at any given time. The incidence of community acquired & hospital acquired S. aureus has been increasing over the past few decades, predominantly due to continuous upsurge in the drug resistant isolates. Moreover, globally the incidence of methicillin resistant S.aureus (MRSA) is progressively increasing. Hence, it would be imperative to screen all healthcare workers, interns and admitted patients for MRSA carriage and to treat all those who are found positive for the same. With the above background, the current study was undertaken to investigate the carrier rate of S. aureus (including MRSA) among hospital unexposed & exposed medical students. METHODS: A total of 181 medical students of Veer Chandra Singh Garhwali Government Institute of Medical Sciences & Research, Srinagar Garhwal, Uttarakhand. Study participants were broadly divided into two groups: hospital exposed group (n=107) and hospital unexposed group (n=74). Nasal swabs were obtained & cultured for the detection of S. aureus. Congo red agar and 0.1% Crystal Violet Assay were performed to observe the ability to form in vitro biofilm by S. aureus. RESULTS: Out of total 181 medical students 29.28% were found to be healthy carrier of S. aureus. Among the hospital exposed group 37.38% and among hospital unexposed group 17.57% were found to be healthy carrier of S. aureus. Only one student (hospital exposed group) was found to be positive for MRSA. Beta-lactamase production was noted in 90.57% strains of S. aureus while the significant rate of slime layer production was observed in 73.58% of strains. CONCLUSION: Prevalence of S. aureus nasal carriage increases with the duration of exposure to the hospital environment. The nasal carriage of S. aureus in medical students indicate the potential danger of dissemination of S. aureus including MRSA from them to the hospitalized patients which in turn complicates the treatment of same.

Mitochondrial hypoxic stress induces widespread RNA editing by APOBEC3G in natural killer cells.

BACKGROUND: Protein recoding by RNA editing is required for normal health and evolutionary adaptation. However, de novo induction of RNA editing in response to environmental factors is an uncommon phenomenon. While APOBEC3A edits many mRNAs in monocytes and macrophages in response to hypoxia and interferons, the physiological significance of such editing is unclear. RESULTS: Here, we show that the related cytidine deaminase, APOBEC3G, induces site-specific C-to-U RNA editing in natural killer cells, lymphoma cell lines, and, to a lesser extent, CD8-positive T cells upon cellular crowding and hypoxia. In contrast to expectations from its anti-HIV-1 function, the highest expression of APOBEC3G is shown to be in cytotoxic lymphocytes. RNA-seq analysis of natural killer cells subjected to cellular crowding and hypoxia reveals widespread C-to-U mRNA editing that is enriched for genes involved in mRNA translation and ribosome function. APOBEC3G promotes Warburg-like metabolic remodeling in HuT78 T cells under similar conditions. Hypoxia-induced RNA editing by APOBEC3G can be mimicked by the inhibition of mitochondrial respiration and occurs independently of HIF-1α. CONCLUSIONS: APOBEC3G is an endogenous RNA editing enzyme in primary natural killer cells and lymphoma cell lines. This RNA editing is induced by cellular crowding and mitochondrial respiratory inhibition to promote adaptation to hypoxic stress.

Stem-loop structure preference for site-specific RNA editing by APOBEC3A and APOBEC3G.

APOBEC3A and APOBEC3G cytidine deaminases inhibit viruses and endogenous retrotransposons. We recently demonstrated the novel cellular C-to-U RNA editing function of APOBEC3A and APOBEC3G. Both enzymes deaminate single-stranded DNAs at multiple TC or CC nucleotide sequences, but edit only a select set of RNAs, often at a single TC or CC nucleotide sequence. To examine the specific site preference for APOBEC3A and -3G-mediated RNA editing, we performed mutagenesis studies of the endogenous cellular RNA substrates of both proteins. We demonstrate that both enzymes prefer RNA substrates that have a predicted stem-loop with the reactive C at the 3'-end of the loop. The size of the loop, the nucleotides immediately 5' to the target cytosine and stability of the stem have a major impact on the level of RNA editing. Our findings show that both sequence and secondary structure are preferred for RNA editing by APOBEC3A and -3G, and suggest an explanation for substrate and site-specificity of RNA editing by APOBEC3A and -3G enzymes.

RNA Editing in Pathogenesis of Cancer.

Several adenosine or cytidine deaminase enzymes deaminate transcript sequences in a cell type or environment-dependent manner by a programmed process called RNA editing. RNA editing enzymes catalyze A>I or C>U transcript alterations and have the potential to change protein coding sequences. In this brief review, we highlight some recent work that shows aberrant patterns of RNA editing in cancer. Transcriptome sequencing studies reveal increased or decreased global RNA editing levels depending on the tumor type. Altered RNA editing in cancer cells may provide a selective advantage for tumor growth and resistance to apoptosis. RNA editing may promote cancer by dynamically recoding oncogenic genes, regulating oncogenic gene expression by noncoding RNA and miRNA editing, or by transcriptome scale changes in RNA editing levels that may affect innate immune signaling. Although RNA editing markedly increases complexity of the cancer cell transcriptomes, cancer-specific recoding RNA editing events have yet to be discovered. Epitranscriptomic changes by RNA editing in cancer represent a novel mechanism contributing to sequence diversity independently of DNA mutations. Therefore, RNA editing studies should complement genome sequence data to understand the full impact of nucleic acid sequence alterations in cancer. Cancer Res; 77(14); 3733-9. ©2017 AACR.

Tuning the presence of dynamical phase transitions in a generalized XY spin chain.

We study an integrable spin chain with three spin interactions and the staggered field (λ) while the latter is quenched either slowly [in a linear fashion in time (t) as t/τ, where t goes from a large negative value to a large positive value and τ is the inverse rate of quenching] or suddenly. In the process, the system crosses quantum critical points and gapless phases. We address the question whether there exist nonanalyticities [known as dynamical phase transitions (DPTs)] in the subsequent real-time evolution of the state (reached following the quench) governed by the final time-independent Hamiltonian. In the case of sufficiently slow quenching (when τ exceeds a critical value τ_{1}), we show that DPTs, of the form similar to those occurring for quenching across an isolated critical point, can occur even when the system is slowly driven across more than one critical point and gapless phases. More interestingly, in the anisotropic situation we show that DPTs can completely disappear for some values of the anisotropy term (γ) and τ, thereby establishing the existence of boundaries in the (γ-τ) plane between the DPT and no-DPT regions in both isotropic and anisotropic cases. Our study therefore leads to a unique situation when DPTs may not occur even when an integrable model is slowly ramped across a QCP. On the other hand, considering sudden quenches from an initial value λ_{i} to a final value λ_{f}, we show that the condition for the presence of DPTs is governed by relations involving λ_{i},λ_{f}, and γ, and the spin chain must be swept across λ=0 for DPTs to occur.