Interference of holon strings in 2D Hubbard model.

The 2D Hubbard model with large repulsion is an important problem in condensed matter physics. At half filling, its ground state is an antiferromagnet (AMF). The dope AMF below half filling is believed to capture the physics of highTcsuperconductors. And the fermion excitation of this dope AMF is theorized as splitting up into holons and spinons that carry charge and spin separately. It is believed that these exotic holons and spinons are the origins of the unusual properties of highTcsuperconductors. Despite the interests in holons and spinons, the direct observations of these excitations remain difficult in solid state experiments. Here, we show that with the rapid advances in the experimental techniques in cold atoms, the direct observation of holons is possible in quantum quench dynamic processes in cold atom settings. We show that the well-known holon-strings generated by the motion of a holon as well as their interferences can be detected by the measurements spin-spin correlations and demonstrate the presence of the Marshall phase associated with a holon string reflecting an underlying AMF background. Moreover, we show that the interferences of the holon strings make a holon propagate anisotropically, with a diffusion pattern clearly distinct from that of spinless fermions. At the same time, we show that these interferences lead to a large suppression in magnetic order in the region swept through by the strings (even to about 95% for some bond). We further demonstrate the Marshall phase of the holon-strings by comparing the dynamics of holon in thetJmodel with that of the so-calledσtJ-model, which is thetJmodel with the Marshall phase removed. The holons in these models propagate entirely differently.

Deep learning radiomics model based on breast ultrasound video to predict HER2 expression status.

Purpose: The detection of human epidermal growth factor receptor 2 (HER2) expression status is essential to determining the chemotherapy regimen for breast cancer patients and to improving their prognosis. We developed a deep learning radiomics (DLR) model combining time-frequency domain features of ultrasound (US) video of breast lesions with clinical parameters for predicting HER2 expression status. Patients and Methods: Data for this research was obtained from 807 breast cancer patients who visited from February 2019 to July 2020. Ultimately, 445 patients were included in the study. Pre-operative breast ultrasound examination videos were collected and split into a training set and a test set. Building a training set of DLR models combining time-frequency domain features and clinical features of ultrasound video of breast lesions based on the training set data to predict HER2 expression status. Test the performance of the model using test set data. The final models integrated with different classifiers are compared, and the best performing model is finally selected. Results: The best diagnostic performance in predicting HER2 expression status is provided by an Extreme Gradient Boosting (XGBoost)-based time-frequency domain feature classifier combined with a logistic regression (LR)-based clinical parameter classifier of clinical parameters combined DLR, particularly with a high specificity of 0.917. The area under the receiver operating characteristic curve (AUC) for the test cohort was 0.810. Conclusion: Our study provides a non-invasive imaging biomarker to predict HER2 expression status in breast cancer patients.

Early recombinant human growth hormone treatment improves mental development and alleviates deterioration of motor function in infants and young children with Prader-Willi syndrome.

BACKGROUND: Recombinant human growth hormone (rhGH) therapy has shown to improve height and body composition in children with Prader-Willi syndrome (PWS), the evidence of early rhGH treatment on motor and mental development is still accumulating. This study explored the time effect on psychomotor development, anthropometric indexes, and safety for infants and young children with PWS. METHODS: A phase 3, single-arm, multicenter, self-controlled study was conducted in six sites. Patients received rhGH at 0.5 mg/m2/day for first four weeks, and 1 mg/m2/day thereafter for up to 52 weeks. Motor development was measured using Peabody Developmental Motor Scales-second edition, mental development using Griffiths Development Scales-Chinese (GDS-C). Height standard deviation score (SDS), body weight SDS, and body mass index (BMI) SDS were also assessed. RESULTS: Thirty-five patients were enrolled totally. Significant improvements were observed in height, body weight, and BMI SDS at week 52; GDS-C score showed significant improvement in general quotient (GQ) and sub-quotients. In a linear regression analysis, total motor quotient (TMQ), gross motor quotient (GMQ), and fine motor quotient were negatively correlated with age; however, treatment may attenuate deterioration of TMQ and GMQ. Changes in GQ and locomotor sub-quotient in < 9-month group were significantly higher than ≥ 9-month group. Mild to moderate severity adverse drug reactions were reported in six patients. CONCLUSION: Fifty-two-week treatment with rhGH improved growth, BMI, mental development, and lessened the deterioration of motor function in infants and young children with PWS. Improved mental development was more pronounced when instituted in patients < 9 months old.

The quantum dynamics of two-component Bose-Einstein condensate: anSp(4,R)symmetry approach.

The compact groups such asSU(n) andSO(n) groups have been heavily studied and applied in the study of quantum many body systems. However, the non-compact groups such as the real symplectic groups are less touched. In this paper, it is revealed that the quantum dynamics of two-component Bose-Einstein condensate can be described by a non-compact real symplectic groupSp(4,R). With this group, an explicit form of the wavefunction in any time of the evolution can be given, meanwhile, this whole time evolution can be shown to correspond to a trajectory in a six-dimensional manifold. By introducing a polar coordinate, we can visualize this six-dimensional manifold in 2d unit disk and reveal the relation between the behavior of the trajectory in this manifold and the eigenenergies of the Hamiltonian. Furthermore, the time evolution of expectation value of a physical observable such as number operator is proven closely related to the behavior of the trajectory in this manifold.

Hypoxic ucMSC-secreted exosomal miR-125b promotes endothelial cell survival and migration during wound healing by targeting TP53INP1.

A hypoxic microenvironment is a common feature of skin wounds. Our previous study demonstrated that three-dimensional coculture of umbilical cord-derived mesenchymal stem cells (ucMSCs) and endothelial cells facilitates cell communication and host integration in skin tissue engineering. Here, we aimed to identify the mechanism by which ucMSCs affect endothelial cells under hypoxic conditions after skin injury. We demonstrate that hypoxia enhances the exosome-mediated paracrine function of ucMSCs, which increases endothelial cell proliferation and migration. In a mouse full-thickness skin injury model, ucMSC-derived exosomes can be taken up by endothelial cells and accelerate wound healing. Hypoxic exosomes lead to a better outcome than normoxic exosomes by promoting proliferation and inhibiting apoptosis. Mechanistically, microRNA-125b (miR-125b) transcription is induced by hypoxia in ucMSCs. After being packaged into hypoxic exosomes and transported to endothelial cells, miR-125b targets and suppresses the expression of tumor protein p53 inducible nuclear protein 1 (TP53INP1) and alleviates hypoxia-induced cell apoptosis. Inhibition of miR-125b-TP53INP1 interaction attenuates the protective effect of hypoxic exosomes. Moreover, artificial agomiR-125b can accelerate wound healing in vivo. Our findings reveal communication between ucMSCs and endothelial cells via exosomal miR-125b/TP53INP1 signaling in the hypoxic microenvironment and present hypoxic exosomes as a promising therapeutic strategy to enhance cutaneous repair.

[Effect of breastfeeding on the development of infection-related diseases during hospitalization in late preterm infants in 25 hospitals in Beijing, China].

OBJECTIVE: To investigate the incidence rate of infectious diseases during hospitalization in late preterm infants in Beijing, China, as well as the risk factors for infectious diseases and the effect of breastfeeding on the development of infectious diseases. METHODS: Related data were collected from the late preterm infants who were hospitalized in the neonatal wards of 25 hospitals in Beijing, China, from October 23, 2015 to October 30, 2017. According to the feeding pattern, they were divided into a breastfeeding group and a formula feeding group. The two groups were compared in terms of general status and incidence rate of infectious diseases. A multivariate logistic regression analysis was used to investigate the risk factors for infectious diseases. RESULTS: A total of 1 576 late preterm infants were enrolled, with 153 infants in the breastfeeding group and 1 423 in the formula feeding group. Of all infants, 484 (30.71%) experienced infectious diseases. The breastfeeding group had a significantly lower incidence rate of infectious diseases than the formula feeding group (22.88% vs 31.55%, P=0.033). The multivariate logistic regression analysis showed that breastfeeding was an independent protective factor against infectious diseases (OR=0.534, P=0.004), while male sex, premature rupture of membranes, gestational diabetes mellitus, and asphyxia were risk factors for infectious diseases (OR=1.328, 5.386, 1.535, and 2.353 respectively, P < 0.05). CONCLUSIONS: Breastfeeding can significantly reduce the incidence of infectious diseases and is a protective factor against infectious diseases in late preterm infants. Breastfeeding should therefore be actively promoted for late preterm infants during hospitalization.

Clinical features and prognosis of patients with thrombotic thrombocytopenic purpura associated with systemic lupus erythematosus: a review of 25 cases.

OBJECTIVE: To report the clinical features of patients with systemic lupus erythematosus (SLE) associated with thrombotic thrombocytopenic purpura (TTP). Their diagnosis, treatment, and prognosis were also discussed. METHODS: A total of 25 TTP-SLE pediatric patients were included in this study. Their clinical symptoms, laboratory findings, disease activity, and renal biopsy were retrospectively reviewed. RESULTS: The median age of the patient cohort was 14 years old. Nine patients were first diagnosed with SLE, followed by the diagnosis of TTP-SLE, whereas 15 patients were diagnosed with TTP and SLE concurrently. All the 25 TTP-SLE patients had decreased platelet count and microangiopathic hemolytic anemia. Fever, rash, edema and neurological symptoms were the main clinical symptoms. Fragmentation of erythrocytes on blood smear and increased LDH were found in all patients. Nineteen patients (76%) had impaired renal function. Renal biopsy showed that most of the patients had lupus nephritis class IV (20%) and TMA (20%). 13 patients (52%) were treated with glucocorticoids in combination with immunosuppressive agent, and 10 patients (40%) were treated with plasma exchange combined with glucocorticoids plus immunosuppressive agent. One patient died due to lung infection; others had disease remission. Fifteen patients had follow-up regularly, and their conditions were stable. CONCLUSION: Patients with TTP-SLE often had moderate to severe lupus disease activity. Testing of LDH level and blood smear should be performed when kidney and neurological symptoms arise in children with SLE. The use of combination therapy, glucocorticoids plus immunosuppressive agent, provided satisfactory clinical outcome. Patients with refractory TTP-SLE will also need plasma exchange therapy.

The Z2 classification of dimensional reduced Hopf insulators.

Hopf insulators are characterized by a topological invariant called the Hopf index which classifies maps from three-sphere to two-sphere, instead of a Chern number or a Chern parity. In contrast to a topological insulator, the Hopf insulator is not protected by any kind of symmetry. By dimensional reduction, we argue that there exists a new type of Z(2) index for 2D Hamiltonian with a vanishing Chern number. A specific model Hamiltonian with this nontrivial Z(2) index is constructed. We also numerically calculate the topological protected edge modes of this dimensional reduced Hopf insulator and show that they are consistent with the Z(2) classification.

[Three PHEX gene mutations in Chinese subjects with hypophosphatemic rickets and literature review].

The clinical data of three Chinese children who had been definitely diagnosed with X-link dominate hypophosphatemic rickets (XLH) by gene mutation analysis of phosphate-regulating gene with homologies to endopeptidases on the X chromosome (PHEX) were retrospectively studied and the relevant literature was reviewed. PHEX gene mutations were detected in all 3 XLH children; a nonsense mutation (c.58C>T) in one case and splicing mutations (c.1645+1G>A, c.436+1G>A) in the other two cases. Among these mutations, c.436+1G>A was novel. As of January 2014, a total of 329 PHEX gene mutations were reported, primarily within three mutation hot spots, throughout the world. Missense mutations accounted for the highest proportion (24%) among all mutations. There is literature showing geographic differences in the total number of XLH subjects and PHEX mutation types across the world. In the current literature, 89 cases of XLH with 28 types of PHEX mutations have been reported in the population of mainland China. Exon 22 is the most frequent mutation site (18%) and missense mutations are the most common type of mutations (61%). It is concluded that exon 22 is the mutation hot spot and missense mutation is the most common type of mutation in the PHEX gene in Chinese XLH patients and that c.436+1G>A detected in this study is a novel PHEX gene mutation in Chinese with XLH.

Body weight changes in breast cancer patients following adjuvant chemotherapy and contributing factors.

Weight gain commonly occurs in breast cancer patients who receive adjuvant chemotherapy. Weight gain may cause psychosocial stress and is associated with patient prognosis and survival. Several factors contributing to weight gain have been identified in Western populations. However, there was lack of information associated with body weight changes following adjuvant chemotherapy in Chinese breast cancer patients. To the best of our knowledge, this is the first such study to be conducted in the Chinese population. A total of 98 patients who received adjuvant chemotherapy following a modified radical mastectomy were included in this study. Their weight was measured prior to the first and following the last cycle of chemotherapy. A weight gain, or loss, of >1 kg following adjuvant chemotherapy was considered to be significant. Cancer stage, treatment modalities, menopausal status and other clinical information were obtained through medical record review. The results revealed that the weight changes ranged from -11 to +9 kg, with a mean value of -0.4±4.4 kg. A total of 66.7% of the patients exhibited weight changes (34.6% gained >1 kg and 32.1% lost weight), whereas 33.3% of the patients maintained a stable weight (P<0.001). Patients aged ≤40 years [odds ratio (OR)=1.429, P=0.028], with a weight of ≥60 kg at diagnosis (OR=2.211, P=0.023), who received ≥4 cycles of chemotherapy (OR=1.591, P=0.039) and a total hormone dose of ≥200 mg (OR=2.75, P=0.013) exhibited a higher risk of weight gain. In conclusion, the body weight changes observed in Chinese breast cancer patient post-adjuvant chemotherapy were different from those observed among Western populations, represented predominantly by weight gain and were reflected by approximately equal percentages of weight gain, stable weight and weight loss.

[Gene analysis and literature review of autosomal recessive polycystic kidney disease].

OBJECTIVE: The purpose of this study was to investigate the clinical and genetic characteristics of autosomal recessive polycystic kidney disease. METHOD: Targeted sequencing was used on a children who was accurately diagnosed as autosomal recessive polycystic kidney disease in Peking Union Medical College Hospital to analyze the major clinical manifestations of the disease. An analysis of the PKHD1 genes was made on the patient, and then verified by polymerase chain reaction (PCR). And the related literature was reviewed also. RESULT: The patient was a boy, 2 years and 3 months old, and had abdominal distention for about one year. The abdominal ultrasound suggested diffuse liver lesions, mild intrahepatic bile duct dilatation, structure disturbance of both kidneys, appearance of multiple strong echo. The child was clinically highly suspected of polycystic kidney disease. Targeted sequencing showed two mutations in exon 32 and exon 50 of PKHD1 gene, respectively, c.4274T > G, leading to p.Leu1425Arg, c.7973T > A, leading to p.Leu2658Ter. Verified by PCR, the father has one mutation of c.4274T > G. CONCLUSION: The clinical manifestations of autosomal recessive polycystic kidney disease are multiple renal cyst, cyst of liver and liver fibrosis, intrahepatic bile duct dilatation. Two mutations (c.4274T > G, c.7973T > A) in PKHD1 gene may be pathogenic.