Bose-Einstein condensation of polar molecules was achieved for the first time; Chang'e-6 completed lunar back sampling and on-orbit sample transfer丨Science and Technology Weekly

Compiled by Zhou Shuyi and Wang Xiang

Bose-Einstein condensation of polar molecules achieved for the first time

Bose-Einstein condensate (BEC) is the fifth state of matter after gas, liquid, solid and plasma. Recently, a new study cooled sodium-cesium molecules (NaCs) to the nanokelvin level (1 nK = 1×10^(⁻⁹) K) and realized the BEC of dipole molecules.

As we all know, the macroscopic objects we see in daily life are composed of a large number of microscopic particles that obey quantum mechanics. A natural question is whether we can find physical phenomena that still have quantum characteristics on a macroscopic scale. In 1924, Bose and Einstein predicted that when the de Broglie wavelength of the particles is greater than the average distance between the particles, the ideal quantum Bose gas will undergo a phase transition. This phenomenon is BEC. Its most notable feature is that below a certain critical temperature, a macroscopic number of particles condense into a single quantum state with zero momentum, forming a macroscopic quantum state, and the thermodynamic properties show non-analytic and discontinuous behavior. In 1995, scientists used atoms to realize BEC for the first time, but more complex polar molecules are difficult to cool to the critical temperature and realize BEC due to their interactions.

Velocity distribution of rubidium atom gas before and after Bose-Einstein condensation. The peak indicates that the atoms are gathered in large numbers in the ground state of the system. | Source: National Institute of Standards and Technology/Science Photo Library

In the new study, the researchers used two microwave fields to manipulate sodium-cesium molecules: one controlled the rotation of the molecules and the other caused them to oscillate. The two microwave fields worked together to orient the molecules in a specific direction, preventing lossy collisions between molecules and reducing molecular losses. Only the hottest molecules were removed, allowing the system to cool further. Ultimately, they cooled the system to about 6 nK and obtained a BEC consisting of more than 1,000 molecules with a lifetime of up to 2 seconds.

The researchers said the new research is expected to open up new avenues for related fields such as quantum computing and quantum simulation.

Does the magic weight loss drug affect sexual function? The drug manufacturer responded

A paper published on May 22 in the International Journal of Impotence Research pointed out that non-diabetic men using semaglutide are more likely to experience erectile dysfunction (ED).

The study was based on real-world data analysis and mainly evaluated the association between the use of semaglutide and the risk of ED in non-diabetic obese men. The data came from the electronic medical record database TriNetX Research. The subjects were men aged 18 to 50 years old, with a BMI>30 (according to the standards set by the WHO, BMI>30 represents obesity) and not diagnosed with diabetes who were prescribed semaglutide after June 1, 2021. The study identified 3094 eligible non-diabetic obese men who received a prescription for semaglutide (treatment group), and an equal number of non-diabetic obese men who had not received a prescription for semaglutide (control group).

The mean age of the treatment and control groups was 37.8 years, but the BMI of the treatment group was higher, with a mean BMI of 38.65 kg/m^2, while the mean BMI of the control group was 37.15 kg/m^2.

The analysis results showed that in the treatment group using semaglutide, 1.47% were diagnosed with ED or used PDE5 inhibitors (a class of drugs for treating ED), which is about 4.6 times that of the control group. In addition, 1.53% of the treatment group were diagnosed with testosterone deficiency, while the figure for the control group was 0.80%. Based on this, the study believes that non-diabetic obese male patients who use semaglutide for weight loss have an increased risk of ED and testosterone deficiency compared with non-diabetic men who have never been prescribed semaglutide.

However, some experts pointed out that the study has many confounding factors and its reliability is questionable.

On June 4, Novo Nordisk China, the pharmaceutical company of semaglutide, stated that according to the approved US Prescription Information (PI) or EU Product Characteristics Summary (SmPC), sexual dysfunction is not a side effect mentioned in the instructions for Wegovy (weight loss version of semaglutide). Novo Nordisk was not involved in the execution or analysis of the study. Its analysis results did not provide sufficient information about the dosage form and dose of semaglutide (at the start and end of treatment) or the duration of treatment. Therefore, it is impossible to confirm whether the dose of semaglutide evaluated in this study has been studied or approved for long-term weight management.

Chang'e-6 completes lunar back sampling and on-orbit sample transfer

According to the National Space Administration, from June 2 to 3, Chang'e-6 successfully completed intelligent rapid sampling in the South Pole-Aitken Basin on the far side of the moon, and packaged the precious lunar far side samples in a predetermined form and stored them in the storage device carried by the ascender.

The international payloads carried by the lander, such as the European Space Agency's lunar surface negative ion analyzer and the French lunar radon detector, worked normally and carried out corresponding scientific exploration tasks. The Italian laser corner reflector installed on the top of the lander became a position control point that can be used for distance measurement on the far side of the moon.

At 7:38 a.m. on June 4, the Chang'e-6 ascender carrying lunar samples took off from the back of the moon. After the 3000 N engine worked for about 6 minutes, it successfully sent the ascender into the predetermined lunar orbit.

At 14:48 on June 6, the ascender successfully completed rendezvous and docking with the orbiter and returner combination in lunar orbit, and at 15:24, the lunar sample container was safely transferred to the returner.

Subsequently, the Chang'e-6 orbiter and returner combination will separate from the ascender and enter a waiting phase in orbit around the moon, preparing to implement lunar-Earth transfer orbit control at an appropriate time. After undergoing key steps such as lunar-Earth transfer and separation of the orbiter and returner, the returner will carry lunar samples to land at the Siziwang Banner Space Landing Site in Inner Mongolia as planned.

In addition, the National Space Administration recently released a series of images taken by the Chang'e-6 lander when it landed on the back of the moon, including images of the landing area taken by the landing camera during the landing process and images of the landing point taken by the panoramic camera. The relevant image data was transmitted back via the Queqiao-2 relay satellite, and the image map was processed by the ground application system.

There are many craters with a diameter of more than ten kilometers distributed in the lower and right parts of the shooting area | Source: National Space Administration

The bottom of the lander is relatively flat, with a small number of bright-colored rocks scattered around. | Source: National Space Administration

This image is made up of color images taken by the panoramic camera on the lunar surface on the north side of the landing site | Source: National Space Administration

Produced by: Science Popularization China

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