Breast Milk Enema and Meconium Evacuation Among Preterm Infants: A Randomized Clinical Trial.

Importance: Delayed meconium evacuation and delayed achievement of full enteral feeding among premature infants are associated with poor short- and long-term outcomes. Identifying a more effective and safer enema for meconium evacuation is imperative for improving neonatal care. Objective: To examine whether breast milk enemas can shorten the time to complete meconium evacuation and achievement of full enteral feeding for preterm infants. Design, Setting, and Participants: This randomized, open-label, parallel-group, single-center clinical trial was conducted from September 1, 2019, to September 30, 2022, among 286 preterm infants with a gestational age of 23 to 30 weeks in the neonatal ward of the Shengjing Hospital of China Medical University in Shenyang. Interventions: Preterm infants were randomly assigned to receive either breast milk enemas or normal saline enemas 48 hours after birth. Main Outcome and Measures: The primary outcomes were time to complete meconium evacuation and time to achieve full enteral feeding. Secondary outcomes were duration of hospitalization, weight at discharge, and duration of total parenteral nutrition. Intention-to-treat and per-protocol analyses were conducted. Results: In total, 286 preterm infants (mean [SD] gestational age, 198.8 [7.9] days; 166 boys [58.0%]) were eligible and included in this study. A total of 145 infants were randomized to the normal saline group, and 141 were randomized to the breast milk group. The time to achieve complete meconium evacuation was significantly shorter in the breast milk group than in the normal saline group (-2.2 days; 95% CI, -3.2 to -1.2 days). The time to achieve full enteral feeding was also significantly shorter in the breast milk group than in the normal saline group (-4.6 days; 95% CI, -8.0 to -1.2 days). The duration of total parenteral nutrition was significantly shorter in the breast milk group than in the normal saline group (-4.6 days; 95% CI, -8.6 to -1.0 days). There were no clinically notable differences in any other secondary or safety outcomes between the 2 groups. Conclusions and Relevance: In this randomized clinical trial testing the effects of breast milk enema on meconium evacuation, breast milk reduced the time to achieve complete meconium evacuation and achieve full enteral feeding for preterm infants with a gestational age of 23 to 30 weeks. Subgroup analyses highlight the need for tailored interventions based on gestational age considerations. Trial Registration: isrctn.org Identifier: ISRCTN17847514.

Clinical effects of breast milk enema on meconium evacuation in premature infants: study protocol for a randomized controlled trial.

BACKGROUND: Delayed meconium evacuation is an important cause of intestinal dysfunction in preterm infants. There are many methods to induce defecation in preterm infants: however, the effects are controversial. Finding a new intervention method to promote meconium evacuation in premature infants is necessary. Therefore, in the proposed study, the effectiveness of breast milk enema on complete meconium evacuation and time to achieve full enteral feeding will be investigated in preterm infants. METHODS/DESIGN: The study is a randomized, open-label, parallel-group, and single-center clinical trial. A total of 294 preterm infants will be recruited and stratified based on gestational age. Then, the infants will be assigned in a randomized block design to the intervention and control groups with a 1:1 ratio. Preterm infants in the control and intervention groups will receive saline enema and breast milk enema, respectively. The primary outcomes will be the time to achieve complete meconium evacuation from birth and time to achieve full enteral feeding from birth in preterm infants. The secondary outcomes will include hospitalization days, body weight at discharge, duration of total parenteral nutrition, cholestasis, and adverse events. DISCUSSION: The results of this trial will determine whether breast milk enema shortens the time to complete meconium evacuation and the time to achieve full enteral feeding in extremely preterm and preterm infants. Furthermore, the study results may provide a new, safe, inexpensive, and easy-to-use intervention to effectively evacuate meconium in preterm infants. TRIAL REGISTRATION: ISRCTN Registry ISRCTN17847514 . Registered on September 14, 2019.

Secular trends of hypertension prevalence based on 2017 ACC/AHA and 2018 Chinese hypertension guidelines: Results from CHNS data (1991-2015).

This study aimed to assess the impact of the 2017 American College of Cardiology and American Heart Association (ACC/AHA) guideline and the 2018 Chinese hypertension guidelines on the different secular trends for hypertension prevalence. A total of 82 665 eligible individuals aged ≥20 years were selected from nine cross-sectional study periods (1991-2015) from the China Health and Nutrition Survey (CHNS). Over the 24-year period, the long-term trend for the prevalence of the 2017 ACC/AHA-defined age-adjusted hypertension showed an increase from 32.2% (95% confidence interval (CI): 31.0%-33.3%) in 1991 to 60.0% (95% CI: 58.6%-61.3%) in 2015 (Ptrend  < 0.001). According to the 2018 Chinese guideline for hypertension, the weighted hypertension prevalence increased from 10.0% (95% CI: 9.4%-10.5%) in 1991 to 28.7% (95% CI: 27.9%-29.6%) in 2015 (Ptrend  < 0.001). However, slopes of increasing prevalence of hypertension were significantly greater according to the 2017 ACC/AHA guideline than that based on Joint National Committee (JNC 7) report (ß = 1.00% vs ß = 0.67% per year, respectively, P = 0.041). Based on the 2017 ACC/AHA definition, the prevalence of stage 1 hypertension and elevated blood pressure significantly increase from 22.3% and 6.9% in 1991 to 31.2% and 10.1% in 2015 (all P < 0.05), respectively. The secular trend for the prevalence of hypertension according to the 2017 ACC/AHA guideline showed a greater rate of increase compared with the prevalence based on the 2018 Chinese hypertension guidelines. Public health initiatives should focus on the current status of hypertension in China because of the possible high prevalence of hypertension and concomitant vascular risks.

The Association of Stage 1 Hypertension Defined by the 2017 ACC/AHA Guideline with Stroke and Its Subtypes among Elderly Chinese.

BACKGROUND: The 2017 American College of Cardiology and American Heart Association hypertension guideline updated stage 1 hypertension definition as systolic blood pressure range from 130 to 139 mmHg or diastolic blood pressure from 80 to 89 mmHg. However, the association of stage 1 hypertension with stroke and its subtypes among the older population in rural China remains unclear. METHODS: This population-based cohort study consisted of 7,503 adults aged ≥60 years with complete data and no cardiovascular disease at baseline from rural areas of Fuxin County, Liaoning province, China. Follow-up for the new cases of stroke was conducted from the end of the baseline survey to the end of the third follow-up survey (January 1, 2007-December 31, 2017). Adjusted Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals with the normal blood pressure as a reference, and calculated population attributable risk was based on prevalence and hazard ratios. RESULTS: During a median follow-up of 12.5 years, we observed 1,159 first-ever incident stroke (774 ischemic, 360 hemorrhagic, and 25 uncategorized). With the blood pressure <120/<80 mmHg as a reference, stage 1 hypertension showed the adjusted hazard ratios (95% confidence intervals) of 1.45 (1.11-1.90) for all stroke, 1.65 (1.17-2.33) for ischemic stroke, and 1.17 (0.74-1.85) for hemorrhagic stroke, respectively. In this study, the population attributable risk values of stage 1 hypertension were 10.22% (2.64%-18.56%) for all stroke and 14.34% (4.23%-25.41%) for ischemic stroke. CONCLUSION: Among adults aged ≥60 years in rural China, stage 1 hypertension defined by 2017 American College of Cardiology and American Heart Association hypertension guideline was independently associated with the increased risk of all stroke and ischemic stroke, excluding hemorrhagic stroke.

Stage 1 hypertension defined by the 2017 ACC/AHA guideline predicts future cardiovascular events in elderly Chinese individuals.

The 2017 American College of Cardiology and American Heart Association (ACC/AHA) hypertension guideline updated stage 1 hypertension defined as systolic blood pressure (SBP) of 130-139 mm Hg or diastolic blood pressure (DBP) of 80-89 mm Hg. However, the impact of 1 hypertension that affects future cardiovascular risk remains unclear among older adults in rural China. The prospective cohort study included 7503 adults aged ≥60 years with complete data and no cardiovascular disease (CVD) at baseline. Follow-up for the new adverse events was conducted from the end of the baseline survey to the end of the third follow-up survey (2007.01-2017.12). Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for blood pressure (BP) classifications and adverse events with normal BP as reference (< 120/80 mm Hg). During the 57 290 person-years follow-up period, 2261 all-cause mortality, 1271 CVD mortality, 1159 stroke, and 347 myocardial infarctions (MI) occurred. Patients with stage 1 hypertension versus normal BP had HRs (95% CI) of 1.068 (0.904-1.261) for all-cause mortality, 1.304 (1.015-1.675) for CVD mortality, 1.449 (1.107-1.899) for stroke, and 1.735 (1.051-2.863) for MI, respectively. In conclusion, among adults aged ≥60 years, stage 1 hypertension revealed an increased hazard of CVD mortality, stroke, and MI, which is complementary evidence for the application of 2017 ACC/AHA hypertension guidelines in an older Chinese population. Therefore, BP control in patients with stage 1 hypertension may be beneficial to reduce the hazard of CVD in elderly Chinese individuals.

Storage of Airy wavepackets based on electromagnetically induced transparency.

The research of Airy beams has attained much attention due to their unique characteristics. Coherent control of Airy beams is important for further light beam manipulation and information processing. In this paper, we experimentally investigate the storage and retrieval of 2D Airy wavepackets in a solid-state medium driven by electromagnetically induced transparency (EIT). The transverse profile of the weak probe pulse is modulated by Airy wavepackets. Under EIT condition, the probe Airy wavepackets are stored into the experimental medium by manipulating the intensity of the control field, and later retrieved by the opposite process. The retrieved Airy wavepackets keep a high similarity compared with those before the storage. Furthermore, the self-healing property of the retrieved Airy wavepackets is investigated. This storage of Airy wavepackets develops the control method of Airy beams, which will be useful in further applications.

Image routing via atomic spin coherence.

Coherent storage of optical image in a coherently-driven medium is a promising method with possible applications in many fields. In this work, we experimentally report a controllable spatial-frequency routing of image via atomic spin coherence in a solid-state medium driven by electromagnetically induced transparency (EIT). Under the EIT-based light-storage regime, a transverse spatial image carried by the probe field is stored into atomic spin coherence. By manipulating the frequency and spatial propagation direction of the read control field, the stored image is transferred into a new spatial-frequency channel. When two read control fields are used to retrieve the stored information, the image information is converted into a superposition of two spatial-frequency modes. Through this technique, the image is manipulated coherently and all-optically in a controlled fashion.

Observation of the fluorescence spectrum for a driven cascade model system in atomic beam.

We experimentally study the resonance fluorescence from an excited two-level atom when the atomic upper level is coupled by a nonresonant field to a higher-lying state in a rubidium atomic beam. The heights, widths and positions of the fluorescence peaks can be controlled by modifying the detuning of the auxiliary field. We explain the observed spectrum with the transition properties of the dressed states generated by the coupling of the two laser fields. We also attribute the line narrowing to the effects of Spontaneously Generated Coherence between the close-lying levels in the dressed state picture generated by the auxiliary field. And the corresponding spectrum can be viewed as the evidence of Spontaneously Generated Coherence. The experimental results agree well with calculations based on the density-matrix equations.

Intensity-dependent effects on four-wave mixing based on electromagnetically induced transparency.

We extend the study on a four-wave mixing (FWM) scheme of contiuous-wave lasers in a hot rubidium vapor when the probe and coupling fields work in the electromagnetically induced transparency (EIT) regime while the pump and signal fields work in the two-photon Raman regime. Our experimental results show that the generated signal field is well contained in an EIT dip of the incident probe field as a result of efficient FWM. We find, in particular, that an optimal FWM process can only be attained when the coupling and pump fields are well matched in intensity. If the probe intensity is far beyond the EIT condition, however, the nonlinear efficiency of energy transfer from the probe field to the signal field will be greatly reduced.

Coherence generation and population transfer by stimulated Raman adiabatic passage and π pulse in a four-level ladder system.

We propose a new scheme for achieving the complete population transfer and the optimal coherence generation between the ground state and the Rydberg state in a four-level ladder system by combining the STIRAP or fractional STIRAP technique and the π pulse technique. We consider, in particular, two different situations where spontaneous emission from the two highest states are neglected or not. Our numerical calculations show that the time width and the delay time of the π pulse are two critical parameters for attaining the maximal population transfer and coherence generation in this scheme.

Efficient frequency conversion induced by quantum constructive interference.

We demonstrate in experiment an efficient cw four-wave mixing scheme with maximal intensity conversion efficiency up to 73% in a double-Λ system of hot rubidium atoms. Relevant theoretical analysis shows that this high conversion efficiency benefits greatly from the constructive interference between two four-wave mixing channels, characterized by two different space-dependent phases.

Controlled light-pulse propagation via dynamically induced double photonic band gaps.

We analyze the optical response of a standing-wave driven four-level atomic system with double dark resonances. Fully developed double photonic band gaps arise as a result of periodically modulated refractive index within the two electromagnetically induced transparency widows. We anticipate that the dynamically induced band gaps can be used to coherently control the propagation of light-pulses with different center frequencies and may have applications in all-optical switching and routing for quantum information networks.

Slowing and storage of double light pulses in a Pr3+:Y2SiO5 crystal.

We experimentally demonstrate the slowing and storage of double light pulses in a Pr(3+):Y(2)SiO(5) crystal using a multilevel-tripod scheme. Owing to double dark-state polaritons of the tripod-type system, two signal pulses can be simultaneously slowed. Also, we realize the simultaneous storage (and retrieval) of double light pulses by switching off (and back on) the control field. Slowing and storage of double light pulses in solids may have practical applications in quantum information and quantum networks.

Three-channel all-optical routing in a Pr3+:Y2SiO5 crystal.

We experimentally demonstrate a three-channel all-optical routing based on light storage in a Pr(3+):Y(2)SiO(5) crystal. By switching off the control field under the condition of electromagnetically induced transparency, the optical information of the probe light pulse can be stored in the crystal. When three retrieve control fields are switched on in the release process, the stored optical information from one light channel can be transferred (or distributed) into three different light channels. Also we show that this all-optical routing can be time-delayed. Such a multichannel all-optical routing in solids may have practical applications in quantum information and all-optical network.

Dual-channel all-optical wavelength conversion switching by four-wave mixing.

We report an experimental demonstration of dual-channel all-optical wavelength conversion switching in hot Rb vapor. In a four-level atomic system, a coupling field and a pump field interact with both (87)Rb and (85)Rb isotopes simultaneously and facilitate the generation of two nonlinear signals when the probe field is applied to the corresponding transition. Each nonlinear signal is switched on and off separately by the pump field at different frequencies based on four-wave mixing and isotope shifts.

Coherence transfer between atomic ground states by the technique of stimulated Raman adiabatic passage.

We experimentally and theoretically demonstrate that the atomic coherence can be completely transferred or arbitrarily contributed among the different levels in a four-level atomic (tripod) scheme by a group of coupled pulse sequences. This technique can be applied to the information conversion in slow-light storage, quantum logical gates, and so on, which is based on the atomic coherence effect.

Transmission and reflection of electromagnetically induced absorption grating in homogeneous atomic media.

We theoretically study the transmission and reflection of the probe travelling wave in an electromagnetically induced absorption grating (EIG), which is created in a three-level Lambda-type atomic system when the coupling field is a standing wave. Using the system, we show that a photonic stop band can exist on one side away from the resonance point in ultracold atomic gas, while there is an enhanced absorption at resonance and small reflection around it in the thermal atomic gas. Because our method can deal with such two cases, it is helpful to further understand the effects of the Doppler effect on atomic coherence and interference.

Slow light based on coherent hole-burning in a Doppler broadened three-level Lambda-type atomic system.

We show theoretically that the propagation of light can be slowed down considerably using the method of coherent hole-burning in a Doppler broadened three-level lambda-type atomic medium without the Doppler-free configurations. The reduction of group velocity of light pulse is achieved by the application of a saturating beam and a strong coupling beam which produce a narrow spectral hole-burning at resonance. We can obtain a larger group index than that using the method of saturation absorption spectroscopy in Doppler-broadened two-level atomic systems.

SHG phase matching in GaSe and mixed GaSe1(1-x)S(x), x < or =0.412, crystals at room temperature.

The optical properties of p-type GaSe and mixed GaSe(1-x)S(x), x=0.04, 0.023, 0.090, 0.133, 0.175, 0.216, 0.256, 0.362, 0.369, and 0.412, crystals were studied to reveal the potentials for phase matching and frequency conversion. Comparative experiment on Er3+:YSGG and CO2 laser SHG at identical experimental conditions is carried out at room temperature. Any change in polytype structure of GaSe1(1-x)S(x) was not found.

SHG in doped GaSe:In crystals.

Optical transmission range and phase matching (PM) conditions for second harmonic generation (SHG) of Er3+:YSGG and CO2 laser in indium doped GaSe:In(0.1, 1.23, 2.32 mass%) are studied in comparison with these in pure and sulfur doped GaSe:S(0.09, 0.5, 2.2, 3 mass%) crystals. No changes in transparency curve are found in GaSe crystals up to 2.32 mass% indium content, but as small change as 0.18 degrees in PM angle for 2.79 microm Er3+:YSGG laser SHG and approximately 0.06 degrees for 9.58 microm CO2 laser emission line SHG are detected. PM properties of the crystals are evaluated as a function of temperature over the range from -165 to 230 degrees C. The value of dtheta/dT, the change in PM angle with variation of temperature, is found to be very small for GaSe:In crystals. While for SHG of Er3+:YSGG laser, dtheta/dT =22"/1 degrees C only, it is as small as -4.9"/1 degrees C for that of CO2 laser radiation. Linear variation of PM angle with temperature increasing is an indicator of absence of crystals structure transformation within temperature range from -165 to 230 degrees C. Thus, application of GaSe:In solid solutions in high average power nonlinear optical systems seems to be prospective.