Tuning the Distance to a Possible Ferromagnetic Quantum Critical Point in A_{2}Cr_{3}As_{3}

Although superconductivity in the vicinity of an antiferromagnetic (AFM) instability has been extensively explored in the last three decades or so, superconductivity in compounds with a background of ferromagnetic (FM) spin fluctuations is still rare. We report ^{75}As nuclear quadrupole resonance measurements on the A_{2}Cr_{3}As_{3} family, which is the first group of Cr-based superconductors at ambient pressure, with A being alkali elements. From the temperature dependence of the spin-lattice relaxation rate (1/T_{1}), we find that by changing A in the order of A=Na, Na_{0.75}K_{0.25}, K, and Rb, the system is tuned to approach a possible FM quantum critical point (QCP). This may be ascribed to the Cr2-As2-Cr2 bond angle that decreases towards 90°, which enhances the FM interaction via the Cr2-As2-Cr2 path. Upon moving away from the QCP, the superconducting transition temperature T_{sc} increases progressively up to 8.0 K in Na_{2}Cr_{3}As_{3}, which is in sharp contrast to the AFM case where T_{sc} usually shows a maximum around a QCP. The 1/T_{1} decreases rapidly below T_{sc} with no Hebel-Slichter peak, and ubiquitously follows a T^{5} variation below a characteristic temperature T^{*}≈0.6 T_{sc}, which indicates the existence of point nodes in the superconducting gap function commonly in the family. These results suggest that the A_{2}Cr_{3}As_{3} family is a possible solid-state analog of superfluid ^{3}He.

[Clinical effects of extra-long lateral femoral supercharged perforator flaps in repair of foot and ankle wounds]

Objective: To investigate the clinical effects of extra-long lateral femoral supercharged perforator flaps in repair of ankle and foot wounds. Methods: From March 2014 to October 2018, 16 patients with foot and ankle injuries were admitted to our hospital and left large area of wounds on foot and ankle after emergency treatment. There were 13 males and 3 females, with age of 27 to 60 years. The area of the wounds ranged from 14 cm×10 cm to 40 cm×17 cm. The wounds were repaired with extra-long lateral femoral supercharged perforator flaps. The widths of flaps in 8 patients were longer than 8 cm, and the bilobed flaps were designed to repair the wounds. The area of the flaps ranged from 12 cm×5 cm to 40 cm×9 cm. During the operation, 54 perforators were detected, with an average of 3.2 perforators in each flap, and 36 source arteries of perforators were detected. The blood vessel trunk of 15 patients was descending branch of the lateral femoral circumflex artery, and their supercharged mode was anastomosis of the bulky perforator of descending branch of the lateral femoral circumflex artery with the oblique branch of the lateral femoral circumflex artery and/or medial femoral circumflex artery or the descending branch of superficial illiac circumflex artery. The blood vessel trunk of 1 patient was oblique branch of the lateral femoral circumflex artery, and the supercharged mode of the patient was anastomosis of the oblique branch of the lateral femoral circumflex artery with the bulky perforator of the descending branch of the lateral femoral circumflex artery. The wounds were covered with the flaps after supercharged blood vessel anastomosis, and blood vessels in the donor sites were anastomosed with those in the recipient sites. The donor site was sutured directly. The survival of the flap after the operation and healing time of the wound, and the flap condition, the two-point discrimination distance of flap in patients who were reconstructed with sensation, the recovery of the ankle function, and the appearance of the donor site during follow-up were recorded. Results: A total of 17 flaps in 16 patients were designed, including 8 bilobed flaps and 9 non-lobulated flaps. Sixteen flaps in 15 patients survived. Vascular crisis occurred in the flap of one patient, and the flap survived when the vascular crisis was relieved by the second operation. The healing time of foot and ankle wounds ranged from 12 to 90 days. All the lateral femoral donor sites healed completely. During follow-up of 8 to 48 months, flaps in 2 patients were slightly bloated and were trimmed in 6 months after the operation. The other flaps were with good appearance, soft texture, good elasticity, and no rupture or ulceration. The two-point discrimination distances of flaps ranged from 7 to 16 mm in 8 patients who were reconstructed with sensation, and the other flaps recovered protective sensation. The flexion and extension function of ankle joint recovered well, and the walking function was not affected significantly. All donor sites formed linear scar, with no deep tissue infection such as osteomyelitis. Conclusions: The application of extra-long lateral femoral supercharged perforator flaps to repair the large area of wounds in foot and ankle can significantly reduce damage to donor sites and has advantages of rich blood supply and good safety, thus it has satisfactory clinical effects.

[Exploring the association between SPRY gene family and non-syndromic oral clefts among Chinese populations using data of a next-generation sequencing study]

OBJECTIVE

To explore the association between SPRY gene family and the risk of non-syndromic oral clefts among Chinese populations, in respect of single nucleotide polymorphisms (SNPs) association and parent-of-origin effects.

METHODS

Based on case-parent design, this study used the data of SPRY gene family in a next generation sequencing study of 183 non-syndromic cleft lip with or without cleft palate (NSCL/P) case-parent trios (549 participants) recruited from 2016 to 2018, to analyze the effects of SNP association and parent-of-origin. The sequencing study adopted a two-stage design. In the first stage, whole exome sequencing was conducted among 24 NSCL/P trios with family history to explore potential signals. Then in the second stage, another 159 NSCL/P trios were used as validation samples to verify the signals found in the first stage. The data of general information, disease features and parental environmental exposures for participants were collected through questionnaires. Blood samples were collected from each participant for DNA extraction and sequencing. Transmission disequilibrium tests (TDT) were conducted to test for the association between SNPs and NSCL/P, while Z score tests were applied to analyze parent-of-origin effects. The analyses were performed using Plink (v1.07). TRIO package in R (v3.5.1). Besides, famSKAT analyses were conducted in the first stage to combine the effect of SNPs located on the same gene, using famSKAT package in R(V3.5.1). Bonferroni method was adopted to correct multiple tests in the second stage.

RESULTS

Twenty-two SNPs in SPRY gene family were included for analyses after the quality control process in the first stage. Based on the variants annotation, functional prediction and statistical analysis, rs1298215244 (SPRY1) and rs504122 (SPRY2) were included in the second verification stage. TDTs in the verification stage revealed that rs1298215244: T>C, rs504122: G>C and rs504122: G>T were associated with the risk of NSCL/P after Bonferroni corrections, where rs504122: G>T was a rare variation. Although the test for parent-of-origin effect of rs1298215244: T>C reached nominal significance level, no SNP showed significant association with NSCL/P through parent-of-origin effect after Bonferroni corrections.

CONCLUSION

This study found that SNPs (including both common and rare variants) among the SPRY gene family were associated with the risk of NSCL/P among Chinese populations. This study failed to detect parent-of-origin effects among the SPRY gene family.

[Study regarding the parent-of-origin effect of WNT pathway genes on non-syndromic cleft lip with or without cleft palate among the Chinese population]

Objective: Non-syndromic cleft lip with or without cleft palate (NSCL/P) is a common birth defect with its genetic evidence widely explored. This study explored the potential the parent-of-origin (PoO) effect of WNT pathway on the risks of NSCL/P, using a case-parent trio design. Methods: Data on the single nucleotide polymorphism (SNP) of WNT genes were selected from a genome-wide association study (GWAS). A total of 806 Chinese non-syndromic cleft lip patients, with or without cleft palate (NSCL/P) case-parent trios, were gathered from an international consortium. PoO effect of WNT pathway genes and its haplotypes were explored by log-linear models. Additional Wald tests were performed to assess: a) the heterogeneity of PoO effect between different maternal exposures, b) the interaction between PoO effect, c) maternal exposure to environmental tobacco smoke (ETS), and d) multivitamin supplementation during pregnancy. The threshold for statistical significance was adjusted as 3.47×10(-4), according to Bonferroni correction. Results: After quality control, a total of 144 SNPs within seven genes were included for analyses, among which 8 SNPs were of potential PoO effect (P<0.05). However, none of them achieved the statistical significance after Bonferroni correction. The haplotype rs4074668-rs12725747 (T-A) on WNT9A showed significant PoO effect, based on the haplotype test for PoO (P=2.74×10(-4)). In addition, no statistically significant interaction was found in further exploration of this haplotype under environmental exposures as ETS or multivitamin supplementation. Conclusions: Genes in the WNT pathway may influence the NSCL/P risks through the potential PoO effect. Particularly, the haplotype rs4074668-rs12725747 (T-A) on WNT9A presented significant PoO effect on NSCL/P, statistically. From this current study, findings on WNT pathway related risks among the NSCL/P, need to be further validated by independent samples in the future.

Short tandem repeats and methylation in the promoter region affect expression of cystathionine beta-synthase gene in the laying hen

Homocysteine can be converted to cysteine via the transsulfuration pathway where cystathionine beta-synthase (CBS) is a rate-limiting enzyme. Homocysteine is thought to play a role in bone remodelling and strength. Previous results indicated that some of the difference in bone strength of end-of-lay hens may be associated with CBS expression level. To investigate if differences in the promoter region of the CBS gene might be responsible for observed differences in gene expression between CBS alleles post mortem- and in-vitro expression studies have been undertaken. Transfection of the DF-1 avian cell line with a series of deletion fragments of the 5' promoter, or constructs containing three CBS allele sequences, with a luciferase reporter revealed that a core region of -155 to +131 bp in the CBS promoter was essential for mRNA expression. We found that a variable number of short tandem repeats (7 nucleotide motif and 6 nucleotide repeats) in the core region of the promoter affecting the transcriptional activity and a strong effect for gene expression. However, methylation of the 6 nucleotide repeats varied between allelic variants and these maybe responsible for differences in promoter activity. Our findings indicated variable short tandem repeats and the differentially methylated sites in the promoter region may be responsible for CBS expression differences in the bone of laying hens.

Correction to: Hair follicles transcriptome profiles in Bashang long-tailed chickens with different plumage colors

The words 'hair follicles' was replaced with 'feather follicles' in the title and the main text.

[Fujian Tulou Family Cohort Study: study design and characteristics of participants and pedigrees in baseline investigation]

Objective: To describe the study design, the characteristics of participants as well as the pedigrees included in the baseline survey of Fujian Tulou Family Cohort Study. Methods: Fujian Tulou Family Cohort Study was a prospective open cohort study with a biological sample bank. A baseline survey was conducted in Tulou areas of Nanjing county in Fujian province from 2015 to 2018, including questionnaire survey, physical and biochemical indicators examinations, and blood sample collection in adults aged ≥18 years. In addition, family relationship of the participants was also recorded. The pedigree information of the juveniles under 18 years old were also collected. Results: The baseline survey included 2 727 individuals in two clans, of whom 2 373 (87.0%) were adults, and 2 126 participants completed questionnaires, physical examinations and biochemical tests. The average age of the 2 126 participants was (57.9±13.3) years, with 39.4% being males. The current smoking rates in male and female participants were 41.2% and 2.1%, respectively. The corresponding rates of current alcohol consumption were 19.0% and 2.6%. For common chronic diseases, the prevalence rates were 51.3% for hypertension, 9.7% for diabetes and 26.7% for hyperlipemia according to the self-reported disease diagnoses, health examination results and biochemical examination results in class Ⅱ or Ⅲ hospitals. Based on the family relationship information and genealogical data, 710 pedigrees were finally identified, consisting of 5 087 family members. The numbers of five, four, three, and two generations pedigrees were 3, 88, 238 and 381, respectively. The pairs of the first to the fifth degree relatives were 12 039, 2 662, 1 511, 202 and 31, respectively. Conclusion: The establishment of Fujian Tulou Family Cohort provides valuable resources for exploring the genetic risk factors, environmental risk factors and gene-environment interactions contributing to the risk of common chronic diseases.

Abstract PD4-11: [18F]Fluciclovine PET tracks cellular glutamine pool size in breast cancer and changes in response to metabolic inhibition

Background: Some forms of triple negative breast cancer (TNBC) rely on glutamine (Gln) metabolism for survival and growth (1), therefore, targeting this metabolic pathway provides a viable strategy for managing TNBC. Drugs that inhibit glutaminase (GLS), a key enzyme of glutaminolysis, are being developed (1,2). [18F]Fluciclovine is a PET imaging agent that enters/exits cells via glutamine transporters and undergoes minimal metabolism. Therefore, we hypothesize, that akin to our prior work with [18F]fluoroglutamine (3), the distribution volume (VT) of fluciclovine obtained from dynamic PET can be used to estimate the cellular glutamine level (pool size) and to mark the effect of pharmacological inhibitors of tumor glutaminase (GLS). We tested this hypothesis in human TNBC and ER+ breast cancer xenograft exhibiting a high and low GLS activity, respectively.

Methods: To make [18F]fluciclovine preparation suitable for mouse imaging, citrate in the formulation was removed and replaced with PBS by eluting through a column (Bio-Rad). Cellular uptake was performed in the presence and absence of Gln transporter inhibitors and GLS inhibitor. In vivo dynamic PET imaging were performed on mice bearing HCC1806 (TNBC) and MCF-7 (ER+ BC) xenografts. Dynamic PET images were analyzed by Logan Plot (PMOD) to estimate VT.

Results: Cellular uptake of [18F]fluciclovine in HCC1806 and MCF-7 cells were sensitively inhibited by cold glutamine (Gln) and GPNA (a pharmacologic inhibitor of ASCT-2), confirming that the uptake is mediated by Gln transporters. The peak uptake in MCF-7 cells was 5-fold higher than HCC1806. In mouse models, VT from in vivo [18F]Fluciclovine PET in MCF-7 tumor is 1.4-fold of HCC1806. These data are consistent with a higher cellular Gln pool size in MCF-7 as the result of its lower GLS activity. After inhibition of tumor GLS activity, VT of [18F]fluciclovine in HCC-1806 tumors was increased by 56% from baseline values (n=2), whereas VT in MCF-7 tumors decreased 1% after treatment (n=2). Only a small change of FDG PET signal (5% decrease, n=5) was detected in TNBC tumors after GLS inhibitor treatment.

Discussions: These data suggest that VT obtained from [18F]fluciclovine PET is sensitive to changes of the Gln pool size induced by GLS inhibition whereas FDG PET is not. Since the Gln pool size is inversely related to the GLS activity, increased VT is consistent with the increased intracellular Gln level when metabolic conversion of Gln to glutamate by GLS is inhibited. Our results suggest that [18F]fluciclovine, an imaging agent approved for prostate cancer imaging, may be useful for assessing glutamine pool size in breast cancer and changes in response to GLS inhibition

Support: R21CA198563, R01CA211337, and Komen SAC130060. We thank Blue Earth Diagnostics for supplies of [18F]fluciclovine.

1.Gross MI, Demo SD, Dennison JB, et al. Mol Cancer Ther 2014;13(4):890-901.

2.Le A, Lane AN, Hamaker M, et al. Cell Metab 2012;15(1):110-21.

3.Zhou R, Pantel AR, Li S, et al. Cancer Res 2017;77(6):1476-84.

Citation Format: Cao J, Choi H, Pantel A, Kranseler D, Lee H, Mankoff D, Zhou R. [18F]Fluciclovine PET tracks cellular glutamine pool size in breast cancer and changes in response to metabolic inhibition [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD4-11.

MicroRNA-150 promote apoptosis of ovine ovarian granulosa cells by targeting STAR gene

To better understand the function of oar-miR-150 in the ovine granulosa cells (GCs) during the estrus cycle, the five turpan sheep were selected for detection of the expression of oar-miR-150 in follicular and luteal ovaries, respectively. Then the granulosa cells treated with oar-miR-150 mimics or negative control (NC) were analyzed by qPCR to assess the expression of genes involved in steroidogenic and apoptosis. Expression of oar-miR-150 was increased in follicular phase compared with that in luteal ovaries. STAR was a target gene of miR-150 with oar-miR-150 mimic or inhibitor and luciferase reporter assay. Overexpression of oar-miR-150 promoted expression of bax, bcl2 and Casp3 expression and declined the expression of STAR, Cyp11a1 and HSD3B1 in vitro. Taken together, these results demonstrate that the oar-miR-150 promote GCs apoptosis through modifying the expression of genes involved in progesterone synthesis.

Effects of Intrauterine Air Bubbles on Embryonic Development in Mice

During murine embryo transfer, air bubbles frequently are loaded with embryos into the transfer catheter, but the role of air bubbles on embryonic development is unclear. This study shows that intrauterine air disrupted embryo spacing, induced deciduoma, and impaired postimplantation development. RNA sequencing showed that the gene expression profile of air-induced deciduoma differed significantly from that of embryo-induced decidua but is similar to tetraploid-induced deciduoma. A subset of 33 common genes was upregulated in the embryo-induced decidua compared with air- or tetraploid-induced deciduoma. These data suggest that the inner cell mass (ICM) plays a key role in regulating decidualization and that the trophectoderm is an intermediate that relays ICM-derived signals to other target cells. Our results may provide an innovative approach for detecting the developmental status of embryos in human reproductive medicine.

Analysis of Genetic Polymorphism and Genetic Distance of 19 Autosomal STR Loci in Jiangsu Han Population

OBJECTIVES

To investigate the distribution of alleles in 19 autosomal short tandem repeat （STR） loci in Jiangsu Han population.

METHODS

Goldeneye^® 20A kit was used to detect 9 025 samples. Genetic analysis was performed on typing data of 19 autosomal STR loci, and genetic distance with other 17 populations was analyzed.

RESULTS

All the 19 autosomal STR loci were consistent with the Hardy-Weinberg equilibrium （P>0.05）, with the heterozygosity 0.616 1-0.916 3, probability of match 0.012 8-0.202 6, discrimination power 0.797 4-0.987 2, probability of paternity exclusion 0.310 8-0.828 8, and polymorphic information content 0.561 7-0.913 6. The cumulative discrimination power and cumulative probability of exclusion were 0.999 999 999 999 999 998 434 1 and 0.999 999 989, respectively. The Jiangsu Han population had close genetic distances with the Han population in Tianjin, Hunan and Jilin, and significant difference with Han population in Aletai region in Xinjiang （P<0.05）.

CONCLUSIONS

The STR allele polymorphism data and population genetic parameters of Jiangsu Han population can provide data support for the forensic application of these STR loci in Jiangsu Han population.

[Association between gestational weight gain and adverse pregnancy outcomes: a prospective study]

Objective: To explore the association between gestational weight gain (GWG) and adverse pregnancy outcomes. Methods: A prospective study was conducted among 1 220 healthy singleton pregnant women in the first trimester of pregnancy, from Chengdu city, Sichuan province. Pre-gestational body mass and other basic information were collected through a set of questionnaires. Weight at the last week before delivery was measured and GWG was classified by IOM criteria (2009). Related information on pregnancy outcomes was collected after delivery, through the hospital information system. Multiple non-conditional logistic regression models were used to test the association between GWG and adverse pregnancy outcomes. Results: In total, data on 1 045 pregnant women were analyzed. Compared with adequate GWG, excessive GWG was associated with the increased risks of cord entanglement and large for gestational age (OR=1.641, 95%CI: 1.197-2.252; OR=1.678, 95%CI: 0.132-2.488), respectively. Additionally, when compared with the adequate GWG, insufficient GWG was associated with the increased risk of preterm delivery (OR=3.189, 95%CI: 1.604-6.341). Conclusions: Both excessive and insufficient GWG appeared associated with the pregnancy outcomes. Weight monitoring should be strengthened for pregnant women to reduce related risks on adverse pregnancy outcomes.

Effect of cervicolumbar coupling on spinal reflexes during cycling after incomplete spinal cord injury

Spinal networks in the cervical and lumbar cord are actively coupled during locomotion to coordinate arm and leg activity. The goals of this project were to investigate the intersegmental cervicolumbar connectivity during cycling after incomplete spinal cord injury (iSCI) and to assess the effect of rehabilitation training on improving reflex modulation mediated by cervicolumbar pathways. Two studies were conducted. In the first, 22 neurologically intact (NI) people and 10 people with chronic iSCI were recruited. The change in H-reflex amplitude in flexor carpi radialis (FCR) during leg cycling and H-reflex amplitude in soleus (SOL) during arm cycling were investigated. In the second study, two groups of participants with chronic iSCI underwent 12 wk of cycling training: one performed combined arm and leg cycling (A&L) and the other legs only cycling (Leg). The effect of training paradigm on the amplitude of the SOL H-reflex was assessed. Significant reduction in the amplitude of both FCR and SOL H-reflexes during dynamic cycling of the opposite limbs was found in NI participants but not in participants with iSCI. Nonetheless, there was a significant reduction in the SOL H-reflex during dynamic arm cycling in iSCI participants after training. Substantial improvements in SOL H-reflex properties were found in the A&L group after training. The results demonstrate that cervicolumbar modulation during rhythmic movements is disrupted in people with chronic iSCI; however, this modulation is restored after cycling training. Furthermore, involvement of the arms simultaneously with the legs during training may better regulate the leg spinal reflexes.

NEW & NOTEWORTHY This work systematically demonstrates the disruptive effect of incomplete spinal cord injury on cervicolumbar coupling during rhythmic locomotor movements. It also shows that the impaired cervicolumbar coupling could be significantly restored after cycling training. Actively engaging the arms in rehabilitation paradigms for the improvement of walking substantially regulates the excitability of the lumbar spinal networks. The resulting regulation may be better than that obtained by interventions that focus on training of the legs only.

[Identification of the core promoter of the pmel gene of Bashang long-tail chickens]

To explore the activity of the pmel core promoter of Bashang long-tail chickens, we constructed dual-luciferase expression vectors and transiently transfected into DF1 cells with Lipofectamine 2000. We measured the luciferase activity with the dual-luciferase detection kit. The 1 268 bp fragment in 5-flanking region of the pmel gene in Bashang long-tail chickens was cloned. The region from -1 200 bp to +68 bp included 2 CpG islands and multiple transcription factor binding sites. We constructed 9 expression vectors with different promoter regions and a mutant vector of the core promoter region of the pmel gene of Bashang long-tail chickens. The core promoter region from -840 bp to +68 bp was identified in the pmel gene. The region from -590 to -525 bp negatively regulated the pmel gene during the transcription process. The -840--590 bp and -525--266 bp regions were positive regulatory regions. The polymorphic sites (-456, -435, -410, -374 and -341) had a significant effect on the promoter activity of the pmel gene.

Clinicopathologic charcterization of sorafenib-induced endoplasmic reticulum stress in human liver cancer cells

Sorafenib (Sor) is clinical standard therapy for advanced hepatocellular carcinoma (HCC). However, detailed molecular mechanism behind Sor-exerted pharmacological effect remains unknown. In this study, sera samples, staged hepatic cancer tissues from Sor-treated patients with advanced HCC were harvested for a group of biochemical tests and immunoassays. Compared to non-treated control, blood contents of alanine transaminase (ALT), aspartate transaminase (AST), alphafetoprotein (AFP), fibroblast growth factor 21 (FGF21) were decreased in Sor-treated HCC patients, while the level of interleukin 10 (IL-10) were increased. As well, reduced triglyceride (TG), total cholesterol (T-CHOL), interferon gamma (IFN-γ), and tumor necrosis factor alpha (TNF-α) levels in sera were checked in Sor-treated HCC patients. In comparison with non-treated cancer sections, Sor-treated HCC cells showed decreased positive cells of proliferative marker for proliferating cell nuclear antigen (PCNA) and metastasized biomarker for cytokeratin 19 (CK19). In addition, elevated immunofluorescence-labeled cells of endoplasmic reticulum (ER)-stress markers of activating transcription factor 6 (ATF6), eukaryotic initiation factor 2α kinase (eIF2α), glucose-regulated protein (GRP-78), X-box binding protein 1 (XBP1) were observed in Sor-treated HCC livers. Further, validated data from Western blot assay exhibited that hepatocellular expressions of ATF6, eIF2α, GRP78, XBP1 in Sor-treated HCC liver cells were up-regulated. Briefly, our present clinicopathologic findings indicate that Sor-induced ER stress may be responsible for therapeutic mechanism against advanced HCC. In addition, induction of intracellular ER stress functions as a promising strategy for treating advanced HCC.

Unusual Interplay between Superconductivity and Field-Induced Charge Order in YBa_{2}Cu_{3}O_{y}

We present a detailed study of the temperature (T) and magnetic field (H) dependence of the electronic density of states (DOS) at the Fermi level, as deduced from specific heat and Knight shift measurements in underdoped YBa_{2}Cu_{3}O_{y}. We find that the DOS becomes field independent above a characteristic field H_{DOS}, and that the H_{DOS}(T) line displays an unusual inflection near the onset of the long-range 3D charge-density wave order. The unusual S shape of H_{DOS}(T) is suggestive of two mutually exclusive orders that eventually establish a form of cooperation in order to coexist at low T. On theoretical grounds, such a collaboration could result from the stabilization of a pair-density wave state, which calls for further investigation in this region of the phase diagram.

Electron Mass Enhancement near a Nematic Quantum Critical Point in NaFe_{1-x}Co_{x}As

A magnetic order can be completely suppressed at zero temperature (T), by doping carriers or applying pressure, at a quantum critical point, around which physical properties change drastically. However, the situation is unclear for an electronic nematic order that breaks rotation symmetry. Here, we report nuclear magnetic resonance studies on NaFe_{1-x}Co_{x}As where magnetic and nematic transitions are well separated. The nuclear magnetic resonance spectrum is sensitive to inhomogeneous magnetic fields in the vortex state, which is related to London penetration depth λ_{L} that measures the electron mass m^{*}. We discovered two peaks in the doping dependence of λ_{L}^{2}(T∼0), one at x_{M}=0.027 where the spin-lattice relaxation rate shows quantum critical behavior, and another at x_{c}=0.032 around which the nematic transition temperature extrapolates to zero and the electrical resistivity shows a T-linear variation. Our results indicate that a nematic quantum critical point lies beneath the superconducting dome at x_{c} where m^{*} is enhanced. The impact of the nematic fluctuations on superconductivity is discussed.

Gene-Gene Interactions among SPRYs for Nonsyndromic Cleft Lip/Palate

Nonsyndromic cleft lip with or without cleft palate (NSCL/P) is a common birth defect with a complex genetic architecture. Gene-gene interactions have been increasingly regarded as contributing to the etiology of NSCL/P. A recent genome-wide association study revealed that a novel single-nucleotide polymorphism at SPRY1 in 4q28.1 showed a significant association with NSCL/P. In the current study, we explored the role of 3 SPRY genes in the etiology of NSCL/P by detecting gene-gene interactions: SPRY1, SPRY2, and SPRY4-with SPRY3 excluded due to its special location on the X chromosome. We selected markers in 3 SPRY genes to test for gene-gene interactions using 1,908 case-parent trios recruited from an international consortium established for a genome-wide association study of nonsyndromic oral clefts. As the trios came from populations with different ancestries, subgroup analyses were conducted among Europeans and Asians. Cordell's method based on conditional logistic regression models was applied to test for potential gene-gene interactions via the statistical package TRIO in R software. Gene-gene interaction analyses yielded 10 pairs of SNPs in Europeans and 6 pairs in Asians that achieved significance after Bonferroni correction. The significant interactions were confirmed in the 10,000-permutation tests (empirical P = 0.003 for the most significant interaction). The study identified gene-gene interactions among SPRY genes among 1,908 NSCL/P trios, which revealed the importance of potential gene-gene interactions for understanding the genetic architecture of NSCL/P. The evidence of gene-gene interactions in this study also provided clues for future biological studies to further investigate the mechanism of how SPRY genes participate in the development of NSCL/P.