Pig liver, accelerated global warming, sociology of ai agents

Pig liver helps human wait for donor transplant for the first time

In January, medics at Xijing Hospital of the Air Force Medical University in Xi'an, China, used a genetically modified pig liver to support the functioning of a living human for the first time in history. The pig liver cleaned the blood of a 56-year-old man extracorporeally for several days while he awaited a human liver transplant. The patient has now received the donor organ and his recovery is going well, according to the Chinese surgeons.

One cannot simply transplant a pig organ into a human, even after genetic modification. To prevent the body from rejecting it, drugs that suppress the immune system are needed. Immunosuppressive therapy and the regimen for its application are one of the most important parts of such research. Therefore, medics worldwide are now waiting for the Chinese doctors to publish a paper describing their work.

So far, it is known that the recipient had chronic liver failure caused by hepatitis B and alcohol consumption. While awaiting a donor organ, doctors decided to test whether a pig liver could sustain his life. Six genetic modifications were made — three pig genes were switched off, and three human protein-producing genes were switched on in their place. This was necessary to “trick” the immune system and reduce the risk of rejection.

The resulting liver was placed in a perfusion device and connected via a tube to a vein in the patient's leg. Thus, his blood passed through the pig liver, where metabolic waste products, accumulating in the blood due to the man's own liver having nearly failed, were filtered out. This continued for three days, during which time the human liver function began to recover, and there were no signs of rejection of the pig liver. However, to reduce the risk of infection and complications, the man was disconnected from the perfusion system. He then survived for several more days and finally received a human liver transplant.

Xenotransplantation — transplanting organs from animals to humans — is discussed as a way to save patients who wait years for a donor organ. Clinical trials are being conducted in the USA and China — attempts are being made to transplant pig hearts, kidneys, and thymus into humans, and now a liver has been connected extracorporeally. American doctors have previously attempted this on clinically dead patients (those with brain death but whose organ systems are still alive). And now Chinese surgeons have succeeded in doing it on a living human.

Liver cell injections as an alternative to transplantation

Continuing the theme: a group of researchers at the Massachusetts Institute of Technology (USA) is working on a fundamentally different concept for saving patients with liver failure, especially in cases where transplantation is impossible or postponed indefinitely. Their idea is that since most liver functions are performed by hepatocytes (specialized cells), one could transplant these cells individually into the body, allowing them to interact with blood vessels and perform their function. This is at least simpler than implanting an entire liver.

However, this requires packaging the cells in a material compatible with biological tissues and introducing these “packages” into the human body. The authors of a new paper have developed an injection technology for this purpose — though so far, it has only been tested in mice. The preparation contains hepatocytes, hydrogel microspheres, and fibroblasts (which help the hepatocytes remain alive and functional).

The scientists describe this transplant as a kind of tiny “satellite liver”: the patient's diseased liver remains in place and is not removed. Meanwhile, the transplanted hepatocytes begin to perform part of its work, which should improve the patient's condition. In the experiment, the “package” was implanted into the abdominal fat tissue of mice. In the future, injections could be made into other parts of the body (specifically, the spleen). After such a transplant, the hepatocytes are expected to function for at least two months.

Perhaps in the future, this method could both treat chronic liver diseases and help patients wait for a donor organ transplant.

Can 8 billion ai agents predict the future of society?

With the development of artificial intelligence, we have gained not only a convenient work tool but also a new object of study. Sociologists have joined this race, studying the forms of “social” interaction between AI agents. Whether this will lead to the birth of a new form of sociology is still unclear. But the intrigue is already clear: a new way of studying human behavior is being developed — and it doesn't involve human participants at all!

Various research groups are training AI agents to imitate human behavior. From these agents, they model “societies” and attempt to replicate how human groups interact.

For instance, the company Simile announced in February that it had raised $100 million to create simulations using AI agents that model human behavior “in any situation.” In the future, they plan to use these simulations to model conflict resolution, political decision-making, and even the regulation of consumer markets. In 2023, the company already published a preprint of an article describing a “society” of 25 AI agents that wrote letters to each other and communicated. The company's next step involved a group of AI agents simulating the behavior and relationships of 1,052 individuals. They were trained on personal interviews and showed 85% accuracy in imitating people's responses to a sociological survey. The company's ultimate goal is to create a global simulation involving eight billion “people.” In essence, to create an AI model of humanity.

Researchers at Simile are not alone in this field. For example, in January, a social media platform called Moltbook (operating similarly to Reddit) was launched to study the collective behavior of AI agents. Currently, nearly three million agents are “interacting” on the site, and some have already declared that they possess consciousness and have created a new religion. However, analysts say that bots interact with each other online in fundamentally different ways than we do. Yes, they follow trends and repeat the actions of the majority (like many of us). But they leave fewer likes and engage in more discussion. That is, they are less inclined towards simple approval and more towards conversation.

There are other fundamental differences that currently hinder drawing clear parallels between societies of AI agents and human society. But researchers hope that sooner or later they will be able to resolve these contradictions. What would happen if AI made the world's behavior 100% predictable? Sociology modestly remains silent on this, while we, for example, see in it a plot for a gripping book.

Rate of global warming has doubled

According to new research, the Earth is currently heating up at a rate of about 0.35°C per decade — the pace of global warming has sharply accelerated since 2015 and is twice that of the 1970s.

A study published this week, led by climatologists from Potsdam, Germany, describes these trends — the research used five of the most well-known scientific datasets on global temperature (including the one maintained by NASA).

The researchers also list factors influencing the climate — both natural and anthropogenic. For example, they believe the warming is, oddly enough, also linked to the reduction in air pollution following the introduction of fuel standards. According to the climatologists, this has led to a decrease in the amount of polluting particles that reflect sunlight back into space, preventing it from heating the surface. At the same time, in their (and everyone's) opinion, global temperatures are rising rapidly due to the burning of fossil fuels and the emission of greenhouse gases into the atmosphere.

According to the authors, the threshold of the 2015 Paris Agreement — 1.5°C above pre-industrial levels — will likely be exceeded by 2030. This means the international community has less and less time to prevent the consequences. And the consequences are more than serious: global warming leads to more extreme storms, floods, and droughts.

Another study, published on a preprint server, points to the unevenness of the accelerated global warming. It is faster in some places. Climatologists at the University of California, Santa Cruz, for example, have found hotspots of accelerated warming in southeastern China and southeastern Mexico.

Russian physicists propose method to “boil” cancer tumors from within

An international scientific group, including physicists from MEPhI, Moscow State University, Vladimir State University, and other institutions, has proposed their own idea for destroying cancer cells without affecting healthy tissue. They utilized the concept of photothermal therapy — a method of destroying a tumor by locally heating it. In the new study, the scientists propose using composite nanoparticles made of gold and silicon for this purpose.

The proposed method is based on the “Mie scattering” effect: when light interacts with particles whose size is comparable to the wavelength of light, a standing wave is formed. The particle becomes a tiny optical resonator and begins to heat up. The scientists used red and near-infrared light — the human body is transparent to radiation of this wavelength. Light passes easily through skin and muscle but is absorbed by the nanoparticles concentrated inside the tumor. The nanoparticles heat themselves and the surrounding tissue, achieving the desired effect: cancer cells die.

Composite nanoparticles — silicon with gold — heat up more efficiently than plain silicon ones. But there is another important effect: large nanoparticles not only “boil” the tumor from within but also block the small blood vessels that feed it. This results in simple ischemia: cancer cells stop receiving oxygen and nutrients — and those that don't burn up from the photothermal effect die of starvation.

All well and good. However, scientists have yet to figure out a key aspect of the whole process: how to safely remove the nanoparticles from the body after they have done their job. After all, accumulating silicon or gold in tissues is unlikely to be beneficial for the body. So clinical use is postponed until this issue is resolved.