Repeated multi-qubit readout and feedback with a mixed-species trapped-ion register.

Quantum error correction is essential for realizing the full potential of large-scale quantum information processing devices1,2. Fundamental to its experimental realization is the repetitive detection of errors via projective measurements of quantum correlations among qubits, as well as corrections using conditional feedback3. Repetitive application of such tasks requires that they neither induce unwanted crosstalk nor impede further control operations, which is challenging owing to the need to dissipatively couple qubits to the classical world for detection and reinitialization. For trapped ions, state readout involves scattering large numbers of resonant photons, which increases the probability of stray light causing errors on nearby qubits and leads to undesirable recoil heating of the ion motion. Here we demonstrate up to 50 sequential measurements of correlations between two beryllium ion microwave qubits using an ancillary optical qubit in a calcium ion, and implement feedback that allows us to stabilize two-qubit subspaces as well as Bell states, a class of maximally entangled states. Multi-qubit mixed-species gates are used to transfer information within the register from the qubit to the ancilla, enabling readout with negligible crosstalk to the data qubits. Heating of the ion motion during detection is mitigated by recooling all three ions using light that interacts with only the calcium ion, known as sympathetic cooling. A key element of our experimental setup is a powerful classical control system that features flexible in-sequence processing for feedback control. The methods employed here provide essential tools for scaling trapped-ion quantum computing, quantum-state control and entanglement-enhanced quantum metrology4.

Height-based formulas for predicting intravascular length of tunnelled neck central venous catheter in paediatric population.

INTRODUCTION: Central venous catheter (CVC) placement is commonly performed in children. We aim to develop simple formulas to predict CVC intravascular length to minimise radiation exposure associated with the procedure. METHODS: 124 paediatric patients who received tunnelled neck CVCs and subsequent CT thorax at Hong Kong Children's Hospital from January 2020 to July 2022 were reviewed retrospectively. Formula development cohorts were subdivided by insertion sites-9 right external jugular vein (REJV), 41 right internal jugular vein (RIJV), 14 left external jugular vein (LEJV), 10 left internal jugular vein (LIJV). Using measurements from CT by two radiologists, formulas predicting the CVC intravascular length based on height and insertion sites were developed using a linear regression model. These formulas were tested with validation cohorts (10 randomly selected cases in REJV and RIJV groups respectively). Validation cohorts were not available for LEJV and LIJV groups due to small sample sizes. RESULT: The goodness-of-fit (R^2) of all formulas are above 0.8. In the validation cohorts, the REJV formula was predictive of intravascular CVC length within 1 cm in 70% of CVC with mean absolute difference of 0.63 cm (SD 0.48 cm), and the RIJV formula was predictive of intravascular CVC length within 1 cm in 80% of CVC with mean absolute difference of 0.67 cm (SD 0.53 cm). CONCLUSION: Intravascular CVC length can be estimated using simple formulas based on height and insertion sites. Further prospective validation of the LEJV and LIJV formulas is needed.

Quantum Harmonic Oscillator State Control in a Squeezed Fock Basis.

We demonstrate control of a trapped-ion quantum harmonic oscillator in a squeezed Fock state basis, using engineered Hamiltonians analogous to the Jaynes-Cummings and anti-Jaynes-Cummings forms. We demonstrate that for squeezed Fock states with low n the engineered Hamiltonians reproduce the sqrt[n] scaling of the matrix elements which is typical of Jaynes-Cummings physics, and also examine deviations due to the finite wavelength of our control fields. Starting from a squeezed vacuum state, we apply sequences of alternating transfer pulses which allow us to climb the squeezed Fock state ladder, creating states up to excitations of n=6 with up to 8.7 dB of squeezing, as well as demonstrating superpositions of these states. These techniques offer access to new sets of states of the harmonic oscillator which may be applicable for precision metrology or quantum information science.

Observation of Quantum Interference between Separated Mechanical Oscillator Wave Packets.

We directly observe the quantum interference between two well-separated trapped-ion mechanical oscillator wave packets. The superposed state is created from a spin-motion entangled state using a heralded measurement. Wave packet interference is observed through the energy eigenstate populations. We reconstruct the Wigner function of these states by introducing probe Hamiltonians which measure Fock state populations in displaced and squeezed bases. Squeezed-basis measurements with 8 dB squeezing allow the measurement of interference for Δα=15.6, corresponding to a distance of 240 nm between the two superposed wave packets.

TB notifications among citizens and non-citizens in Taiwan.

Substantial under-notification of TB among non-citizens has been noted previously. Foreign workers with TB who were deported previously could stay for anti-TB treatment since 2014. We assessed whether TB notification improved.We used the National Health Insurance (NHI) reimbursement database to identify potential TB cases that required notification. We matched potential TB cases with the national TB registry to determine whether they had been notified. Cases notified within 7 days of the initiation of anti-TB treatment were classified as having timely notification.Of 53,208 potential TB cases identified in 2016-2020, 96.6% had been notified. The notification proportion increased from 95.5% in 2016 to 97.1% in 2020 among citizens and from 89.0% in 2016 to 96.9% in 2020 among non-citizens. Factors significantly associated with non-notification among non-citizens were previously notified TB (aOR 35.5, 95% CI 17.7-70.9), without health insurance (aOR 15.4, 95% CI 9.3-25.2) and having only one visit to health care facilities in 6 months (aOR 2.3, 95% CI 1.4-3.8). The proportion of TB cases notified within 7 days was 87% overall, 86.2% among citizens, and 96.5% among non-citizens.TB notification has improved, especially among non-citizens, following a policy change that allows foreign workers to stay for anti-TB treatment..

Work rehabilitation for migrant workers with work injury--the magic of Chinese paper cutting.

As China has gradually transformed from agricultural economy into industrial economy since 1978, occupational injuries and diseases become a serious social problem in China. For occupational rehabilitation professionals, helping workers with occupational injuries and diseases, return to work and re-integrate to community are the ultimate goals of occupational rehabilitation. This article reports a new indigenous initiative with cultural notions in occupational rehabilitation piloted by Guangdong Provincial Rehabilitation Center. Case studies reflected that by learning and practicing traditional Chinese paper cutting, workers with occupational injury and disease could regain their self confidence, identity their strengths, learn more vocational skills as well as to re-integrate into community.

Pilot project in developing community rehabilitation service for migrant workers suffering from pneumoconiosis in Mainland China.

Pneumoconiosis is one of the major occupational health problems in China and increasing numbers of migrant workers suffered from this occupational disease after working in a dusty environment for few years. These migrant workers panicked after being diagnosed as suffering from pneumoconiosis and facing physiological disturbances including progressive dyspnea, respiratory failure or complications like silico-tuberculosis after their return to their rural village. This article reviews the preliminary results of a community rehabilitation pilot project conducted in a rural village in Guizhou, one of the provinces in southwest China. It shares the joint effort of professionals from Guangdong Province and Hong Kong SAR on supporting the migrant workers to manage and cope with this occupational disease. Finally, strategies including early intervention were suggested to help migrant workers to manage the disease. Most importantly, occupational health promotion and prevention were urged as the measures of utmost importance in reducing the risk for migrant workers suffering from pneumoconiosis.

Summary report of action research on occupational rehabilitation and community re-integration of migrant workers with work injuries in Mainland China.

This article is a summary of an action research exploring the strategies to initiate the occupational rehabilitation and community re-integration of migrant workers with work injuries in Guangdong Province, China. Using two cases of rehabilitation intervention for workers with work injury, a case management model of occupational rehabilitation and community re-integration was illustrated, in the different phases of rehabilitation. Finally, some key elements in supporting occupational rehabilitation and community re-integration for migrant workers with work injury in China were highlighted.

Surgical complications in parenteral Subutex abusers.

INTRODUCTION: There were anecdotal reports of an increase in the admissions of parenteral Subutex abusers to our hospital over the past five months. This case study aimed to analyse the surgical complications related to parenteral Subutex abuse and describe the demographics of this group of patients. METHODS: We reviewed all admissions to our hospital between July and November 2005. Only parenteral Subutex abusers were included in this case study. RESULTS: A total of 53 parenteral Subutex abusers were admitted during this period. 31 had surgical complications, while 22 presented with medical ones. Of the surgical patients, 12 had cellulitis and thrombophlebitis, six developed abscesses of the limbs, ten were patients with ischaemia and gangrene of the digits and limbs, one had septic arthritis, one had necrotising fasciitis, and one had a pseudoaneurysm of the femoral artery. There were no reported mortalities. Only nine patients needed surgical interventions. Most of the patients are young with a mean age of 34.2 years. There was a male predominance of 92.4 percent (49 out of 53). Malays are more frequently affected (72 percent, n=38), followed by Indians (15 percent, n=8), and Chinese (13 percent, n=7). CONCLUSION: Parenteral Subutex abuse is a rising concern in Singapore. Many patients present to the surgical and orthopaedic departments for limb and vascular complications. Surgery has a limited role in their management, and most are treated conservatively and expectantly. The solution to this emerging trend requires inter-hospital and ministerial collaboration.

Does enhanced diabetes management reduce the risk and improve the outcome of tuberculosis?

SETTING: The Bureau of National Health Insurance (NHI) has implemented a pay-for-performance (p4p) programme for diabetes mellitus (DM) in Taiwan. OBJECTIVE: To investigate whether patients with DM enrolled in the p4p programme (DM-p4p) are less likely to develop tuberculosis (TB) and whether they have a better outcome than patients with DM not enrolled in the p4p programme (DM-non-p4p) if they do develop TB. DESIGN: A random sample of 79,471 DM-p4p, 100,000 DM-non-p4p and 100,000 non-diabetic patients (non-DM) was obtained from the 2008-2009 NHI database, and the patients were matched with the National TB Registry to determine whether they had developed TB by the end of 2010. RESULTS: The average annual incidence of TB was respectively 259.9 (95%CI 230.2-293.4), 137.5 (95%CI 116.4-162.5) and 74.1 (95%CI 59.0-93.0) per 100,000 population among DM-non-p4p, DM-p4p and non-DM patients. The relative risk of death over treatment success was 1.79 (95%CI 1.05-3.04) among DM-non-p4p and 1.69 (95%CI 0.84-3.40) among non-DM patients, relative to DM-p4p patients. CONCLUSIONS: Enhanced case management of DM reduced risk and improved outcomes of TB among patients with DM.

Estimation of a general time-dependent Hamiltonian for a single qubit.

The Hamiltonian of a closed quantum system governs its complete time evolution. While Hamiltonians with time-variation in a single basis can be recovered using a variety of methods, for more general Hamiltonians the presence of non-commuting terms complicates the reconstruction. Here using a single trapped ion, we propose and experimentally demonstrate a method for estimating a time-dependent Hamiltonian of a single qubit. We measure the time evolution of the qubit in a fixed basis as a function of a time-independent offset term added to the Hamiltonian. The initially unknown Hamiltonian arises from transporting an ion through a static laser beam. Hamiltonian estimation allows us to estimate the spatial beam intensity profile and the ion velocity as a function of time. The estimation technique is general enough that it can be applied to other quantum systems, aiding the pursuit of high-operational fidelities in quantum control.

[HOXD13 polyalanine tract expansion in synpolydactyly: mutation detection and prenatal diagnosis in a large Chinese family].

OBJECTIVE: Synpolydactyly (SPD, MIM 186000), also known as syndactyly type II, is a dominantly inherited limb malformation with incomplete penetrance and variable expressivity. Polyalanine tract expansion in HOXD13 has been shown to be the disease-causing mutation in SPD. The present study was designed to identify mutation in HOXD13 and to provide prenatal diagnosis, in a large Chinese SPD family consisting of 54 individuals. METHODS: The proband and 4 other affected individuals in the family were evaluated physically and radiologically to ascertain the SPD phenotype. Genomic DNA was extracted from peripheral blood samples obtained from 18 family members (9 affected and 9 unaffected), and from amniotic fluid and chorionic villus samples obtained from the proband during her two consecutive pregnancies. With the use of a pair of specific primers, a fragment of 161bp was amplified by polymerase chain reaction (PCR) to cover the imperfect GCN triplet repeat sequence in exon 1 of HOXD13 encoding the 15-residue polyalanine tract. The PCR products were detected by agarose gel electrophoresis, and sequenced after cloning into pMD18T vector. To confirm prenatal diagnosis, haplotype analysis was also performed by allele-typing three microsatellite markers, including the intronic CA repeats in HOXD13. RESULTS: Digital and radiographic findings indicated a typical SPD phenotype in the family. These included 3/4 finger syndactyly and 4/5 toe syndactyly with an extra digit in the syndactylous web. Unilateral finger syndactyly in the proband, unilateral toe syndactyly in 2 individuals, bilateral brachydactyly of the fifth toes in 1 individual, and clinodactyly of the fifth fingers in 4 individuals were also observed, indicating variable expressivity. Gel electrophoresis of the PCR products showed an additional longer fragment in all 9 affected individuals but not in the unaffected ones. Sequence analysis of the longer fragment revealed a 9-alanine expansion. The expansion was detectable in DNA from the amniotic fluid and chorionic villus samples. Furthermore, haplotype analysis ruled out potential contamination of the maternal DNA. These suggested that the two fetuses carried the same polyalanine expansion. CONCLUSION: HOXD13 polyalanine expansion was detected in a large Chinese family with SPD and prenatal diagnosis of two affected fetuses was achieved. This is the first report on prenatal diagnosis of SPD by detecting the HOXD13 polyalanine expansion in the Han population of the Chinese mainland.

Quantum optics. Quantum harmonic oscillator state synthesis by reservoir engineering.

The robust generation of quantum states in the presence of decoherence is a primary challenge for explorations of quantum mechanics at larger scales. Using the mechanical motion of a single trapped ion, we utilize reservoir engineering to generate squeezed, coherent, and displaced-squeezed states as steady states in the presence of noise. We verify the created state by generating two-state correlated spin-motion Rabi oscillations, resulting in high-contrast measurements. For both cooling and measurement, we use spin-oscillator couplings that provide transitions between oscillator states in an engineered Fock state basis. Our approach should facilitate studies of entanglement, quantum computation, and open-system quantum simulations in a wide range of physical systems.

Stereospecific anionically promoted transannular hydride shifts in medium-ring hydroxy ketones. Probe of their reversibility and the potential for regiocontrol.

Examples are provided of stereospecific transannular oxidation-reduction processes involving the conjugate bases of delta-hydroxy ketones in a nine-membered ring setting. The ability to control the direction of these equilibria by proper modulation of the solvent environment and level of hydroxyl group protection is demonstrated. MM3-derived steric energies of the isomer pairs suggest that the equilibrium distributions are the outcome of the extent to which intramolecular hydrogen bonding forces are disrupted by polar solvent molecules when present.

The expression of DAZL1 in the ovary of the human female fetus.

OBJECTIVE: To determine whether DAZL1 is expressed in human fetal ovarian tissue. DESIGN: The presence of DAZL1 expression was determined by reverse transcriptase polymerase chain reaction (RT-PCR). SETTING: Academic tertiary care medical center and research unit of university. PATIENT(S): Five female abortuses between the 19th and 22nd week of gestational age. INTERVENTION(S): Fetal ovarian tissues were collected immediately after the cessation of the heart beat. MAIN OUTCOME MEASURE(S): The product of RT-PCR. RESULT(S): DAZL1 expression was detected in all five samples. CONCLUSION(S): DAZL1 is not only expressed in human testes but also in ovaries. It may play a role in germ cell survival and gonad development in both sexes.

Ultrarapid cryopreservation of human embryos: experience with 1,582 embryos.

OBJECTIVES: To demonstrate the effectiveness of ultrarapid cryopreservation in human embryos. DESIGN: Retrospective study. SETTING: An IVF unit of a medical center. PATIENT(S): All cases received ultrarapid freezing (URF) of embryos and frozen embryo transfer. INTERVENTION(S): Embryos were placed in phosphate-buffered saline (PB1) + 20% maternal serum (MS) for 5 minutes. Embryos were loaded to the straws containing PB1 + MS + 0.25 M sucrose (SUC) + 3.5 M dimethyl sulfoxide for 3 minutes, and then were stored in a liquid nitrogen tank. Embryos were thawed in a 37 degrees C water for 6 seconds and then cultured in PB1 + MS + SUC for 10 minutes. Embryos were transferred into PB1 + MS for 5 minutes and were transferred into patients. MAIN OUTCOME MEASURE(S): The embryo grades before and after URF, the survival and transferred embryo numbers, and the pregnancy and abortion rates were analyzed. RESULT(S): A total of 1,582 embryos were thawed, of which 1,273 (80.5%) embryos were transferred and 1,032 (65.2%) embryos survived with > or = 50% intact blastomere. The embryo numbers with grade I or II before and after freezing and thawing were 1,110 (70.2%) and 790 (50.0%). The mean embryo numbers per transfer was 5.0. Twenty-eight pregnancies (11.4% per transfer) were established, which included 5 miscarriages, 1 ectopic pregnancy, 4 preterm and 18 term deliveries. CONCLUSION(S): Ultrarapid freezing is worthy of reconsideration for embryo cryopreservation.

Recombinant human leukemia inhibitory factor enhances the development of preimplantation mouse embryo in vitro.

OBJECTIVE: To assess the effect of recombinant human leukemia inhibitory factor (rhLIF) on mouse embryos in vitro. DESIGN: Controlled prospective study. SETTING: Academic research environment. ANIMAL(S): Female CB6F1 mice between 6 and 8 weeks old. INTERVENTION(S): Mice were divided randomly into three groups, which included a control group in an in vivo study (group I) and two groups in an in vitro study (groups II and III). Mice were killed at 116-120 hours (group I) and 44-48 hours (groups II and III) after hCG injection. Two-cell embryos (groups II and III) and blastocysts (group I) were obtained. Embryos in group II were cocultured with human tubal fluid (HTF) + 0.5% human serum albumin and in group III with HTF + rhLIF (1,000 U/mL) under paraffin oil. MAIN OUTCOME MEASURE(S): The embryonic numbers in different stages were recorded and compared. RESULT(S): Similar early embryo development to the four- to eight-cell and morula stages was noted between groups II and III (87.3% versus 91.0% and 74.6% versus 87.1%, respectively). However, further embryo development to the blastocyst, expanded blastocyst, and hatching blastocyst in group II (48.1%, 31.7%, and 18.5%, respectively) was lower than that in group III (83.6%, 53.7%, and 37.8%). CONCLUSION(S): RhLIF does not provide obvious stimulation in the early mouse embryo. However, rhLIF has positive effects on preimplantation blastocyst growth, differentiation, and hatching.

Clinical and electroencephalographic findings in early and late onset benign childhood epilepsy with occipital paroxysms.

Twenty-six patients were studied who had the clinical and electroencephalographic features of benign childhood epilepsy with occipital paroxysms (BCEOP) as defined by the Commission of the International League Against Epilepsy (ILAE). Twelve patients were characterized as having early-onset benign childhood occipital seizures (EBOS) susceptible syndrome, as described by Panayiotopoulos, and 14 patients had late onset childhood idiopathic occipital seizures (LOS). Patients with symptomatic epilepsy and whose EEGs exhibited occipital spikes were excluded. The age of onset of the EBOS group ranged from 2.6 to 9.4 years (mean: 4.9+/-1.7 years), which was significantly younger than the LOS group (range: 4-12 years, mean:8.4+/-2.5 years). Both sexes were equally affected. The patients in the EBOS group had less frequent and longer seizures, ictal vomiting, more frequent deviation of the eyes, adversive seizures and more frequent nocturnal and secondary generalized seizures (P<0.05). By comparison, patients in the LOS group had a higher incidence of seizures, shorter duration of seizures and more frequent diurnal onset (P<0.01); also, although not statistically significant, the LOS group had more frequent visual hallucinations and headaches. The EEG topography in both groups showed at either side of occipital area typical paroxysms that were unilateral or bilaterally synchronous. Neither group had dipoles according to scalp voltage mapping. The clinical prognoses were favorable for both groups. To distinguish EBOS from LOS, detailed description of the age of onset, motor symptoms, visual symptoms, presence of eye deviation and diurnal or nocturnal occurrence are essential.

Clinical significance of cell differentiation in hepatocellular carcinoma.

BACKGROUND/AIMS: Hepatocellular carcinoma is commonly found in Asian countries and prognosis still remains unsatisfactory due to recurrence after surgical tumor resection. METHODOLOGY: We try to demonstrate the recurrence and survival time in 99 surgical patients grading by tumor cellular differentiation from surgical specimen. RESULTS: The rates of well, moderate, and poor differentiation were encountered in 21 cases (21.2%), 61 cases (61.6%) and 17 cases (17.7%), respectively. Small tumor (< 3 cm) was found in only one (5.9%) in the poor differentiation group and 38.1% and 37.7% in the well and moderate differentiation groups. Capsular invasion was found in 13 (61.9%), 39 (63.9%) and 7 (41.1%) in the well, moderate and poor differentiation group, respectively. We found 41.9% (18/43) and 22.4% (13/58) to be tumor free in capsule invasion (-) and (+) after a period of 18.1 and 29.9 months, respectively. However, the recurrent time was 10.6 and 11.3 months, respectively with no significant difference (p > 0.05). Vascular invasion was more frequent in the poor differentiation group (76.5%) than the well (23.8%) and moderate (60.7%) differentiation groups (P < 0.05). We found 23.5% (4/17) and 35% (21/60) to be tumor free but the recurrence time was 6.5 and 14.1 months for the vascular invasion (-) and (+), respectively. The residual median survival times were 6.5 and 14 months after recurrence, respectively. The tumor recurrence rates were 52.7% (11/21), 52.4% (32/61), and 35.5% (6/17) and recurrence times were 11.7, 11.9, and 4.5 months for the well, moderate and poor differentiation group respectively totally. The recurrence time of young age group (< 39 years old) was shorter than the others and there was no patient of well differentiation less than 40 years old. The recurrence time was shorter in the poor differentiation group but there was no significant difference according to age group. The median survival times were 22.2, 22.9, and 9.5 months for each group, respectively. CONCLUSIONS: Differentiation of hepatocellular carcinoma cell had a clinical significance and was found to be positively correlated with the invasive proclivity. The median survival time was longer in both the well and moderate differentiation group, but not in the poor differentiation group. The clinical data revealed that the extended operations performed upon the patients with poor differentiation effected the recurrence time but not the survival time.

Sclerotherapy--an adjuvant therapy to endometriosis.

OBJECTIVE: Recurrent endometriomas after medical or surgical treatment is a difficult clinical problem for those patients who wish to perform ovulation induction. Therefore we tried to investigate the efficacy of sclerotherapy as an adjuvant management before ovulation induction to preserve more ovarian tissue for folliculogenesis in ART program. METHODS: Thirty-two patients with persistent or recurrent endometrioma after surgical or medical treatment were included in this study. Transvaginal ultrasound needle guided aspiration of the cyst followed by tetracycline instillation was performed before ovulation induction. RESULTS: There is an encouraging clinical pregnancy rate of 34.37%. Also, there is a disappointing recurrent rate of 46.87% in 12 months follow-up course. CONCLUSION: The increased interest in cost-effective outpatient therapy and the expected difficulty in surgical treatment of recurrent endometriomas made aspiration and sclerotherapy of endometrioma an attractive option before ovulation induction.