From VOA Learning English, this is the Health & Lifestyle report.
Our brains are protected by our skull.
But that is not the only protection it has.
A natural barrier around our brains prevents germs and other damaging substances in the
blood from entering the brain.
Doctors call this protection the "blood-brain barrier."
However, it does more than protect.
This barrier also stops medicines from entering the brain.
Doctors have trouble using drugs to treat brain tumors, Alzheimer's and other diseases
affecting the brain.
So researchers have been trying to find safe ways to get drugs through the barrier.
At Imperial College, London, researchers have been performing experiments with mice.
Doctor James Choi is a leader of this research effort.
He describes the blood-brain barrier as a secure entry point -- what he calls border
patrol.
This keeps out harmful germs or pathogens.
But it also keeps out good things.
"You can think of it as a kind of gateway, or border patrol that is saying the brain
needs glucose, that's allowed in.
All the foreign pathogens -- you're stopped at the door.
You're not allowed to come into the brain."
He and other researchers have shown that high frequency sound waves can help open parts
of the blood-brain barrier.
For this to work, the sound waves must pass through a thick substance or gel.
The researchers say the method is much like ultrasound imaging tests used on pregnant
women.
First, researchers injected very small bubbles into the bloodstream.
Then they added soundwaves to make the bubbles vibrate.
This caused cells in the blood vessel walls to stretch, enabling drugs to reach the brain.
Similar experiments are being performed at Sunnybrook Health Sciences Centre in Toronto,
Canada.
Back in 2015, researchers at Sunnybrook became the first to break the blood-brain barrier
to treat a brain tumor.
In late July 2018, Sunnybrook reported on the latest research.
The New York Times newspaper reports that Dr. Nir Lipsman led the study.
In the statement, Lipsman described the project as a "major goal of neuroscience" for years
adding that it is "exciting."
Six Alzheimer's patients were part of a small test at Sunnybrook.
Lipsman and his team wanted to see if targeted sound waves could break a hole in the blood-brain
barrier for a brief period.
Dr. Sandra Black worked with Lipsman on this trial.
She says the experiment showed that the barrier opened.
It let some harmless fluid flow in, and then it closed back up.
"It just took two ultrasound treatments to show that the blood-brain barrier can be opened.
It's very exciting, I feel quite emotional about it because there's a lot riding on this,
and it's a whole new world of possibilities.
But we have to take one step at a time, we have to make sure it's safe."
The researchers add that as the technology improves, doctors will be able to target very
small areas of the brain.
They hope to target only the areas that need treatment.
Dr. James Choi adds that this kind of targeting will be an important part of future treatments.
"We can make large beams, small beams.
We can steer the beam to any location in the brain.
So the technology's so advanced at this point where we can actually deliver the drug to
any region of the brain."
It may be a long time before doctors can use this form of treatment.
However, as Alzheimer's cases increase around the world, scientists are trying every way
possible to help patients.
I'm Anna Matteo.
A court in Cambodia on Thursday extended by six months the pre-trial detention of Kem
Sokha, the former leader of the country's main opposition party.
Sokha has already been detained for almost a year.
His supporters had hoped Sokha would soon be released, especially following the pardoning
and release of 14 opposition activists earlier this week.
One of Sokha's lawyers said the court ruled in a closed-door hearing that Sokha's continued
detention was necessary for national security.
Sokha was the leader of the Cambodian National Rescue Party (CNRP).
He was arrested last year and charged with treason.
His party was dissolved last November.
Sokha is accused of leading a plan to destroy the government in a US-backed revolution.
In last month's elections, Prime Minister Hun Sen's Cambodian People's Party won all
125 seats in the National Assembly, extending its 33-year hold on power.
Hun Sen said Wednesday of Sokha's case, "What is there to be pardoned?
This is the case of treason."
Hun Sen, however, had asked for pardons for several other jailed opposition activists.
Meach Sovannara, the former head of information and media for the CNRP, was among the 14 freed
earlier this week.
He had been given a 20-year sentence for making a speech at an opposition rally in 2015.
Sovannara has said he will return to politics.
He remains hopeful that a multi-party democracy can be restored in Cambodia.
Political expert Meas Nee told VOA that he believes the government is unsure of what
to do with Sokha.
If they release him, he could rebuild his party.
If they find him guilty, the United States will likely place economic sanctions on Cambodia.
The main piece of evidence against Sokha is a 2013 speech in which he said he had received
U.S. support and help for his political plans.
I'm Caty Weaver.
The Campaign to Stop Killer Robots is urging the United Nations to begin talks about banning
the use and development of autonomous weapons systems.
Representatives from more than 70 countries are attending a five-day meeting in Geneva
of the Convention on Conventional Weapons.
Autonomous weapons systems are military robots that can independently search and attack targets
based on their programming.
They are often called killer robots.
The Campaign to Stop Killer Robots is a worldwide coalition of 76 organizations in 32 countries.
Members include Human Rights Watch, Amnesty International, Mines Action Canada and the
Nobel Women's Initiative.
Activists say that support is growing for countries to negotiate a ban on the devices
during the yearly CCW meeting in late November.
The Campaign to Stop Killer Robots reports that 26 countries have joined the call for
a ban since the last CCW meeting in April.
The group says China is agreeable to a ban on using these weapons, though not on their
development.
The coalition also says Russia has announced its support for a non-binding agreement.
Mary Wareham of Human Rights Watch runs the Campaign to Stop Killer Robots.
She says pressure is increasing on the United States and other countries to support a ban
on fully autonomous weapons.
"All of the ingredients are there for states to take action now," Wareham said.
"The CCW operates by consensus...We will find out on Friday if any country wants to block
the consensus for the proposed mandate."
The proposed mandate is to negotiate a legally binding agreement by the end of 2019.
During the last meeting, France, Israel, Russia, Britain and the United States all rejected
moves to ban these weapons systems.
Activists say legally binding agreements must be passed to guarantee human control over
the use of deadly force.
They say to fail in this would violate internationally accepted morals.
I'm Phil Dierking.
The United States Justice Department on Thursday sided with Asian-American students suing Harvard
University over its consideration of race in admissions.
The department said in a court filing Thursday that Harvard has failed to demonstrate that
it does not discriminate on the basis of race.
It noted what it described as "substantial evidence" that Harvard is carrying out what
the department called "racial balancing."
Attorney General Jeff Sessions added, "No American should be denied admission to school
because of their race."
The Trump administration has been pushing for admissions policies that do not use race
in the consideration process.
In 2014, the group Students For Fair Admission or SFFA argued that Harvard unfairly treats
Asian-Americans who have strong school records.
The Ivy League school denied the accusation.
It said it does not discriminate and will fight to defend its right to consider race
in admissions.
The U.S. Supreme Court permits colleges and universities to consider race in admissions.
But it says this must be done for the narrow purpose of creating a mix of ethnicities at
schools.
The court also says the practice should be limited in time.
And the court bars the establishment of acceptance levels based on race.
The case between the SFFA and Harvard could become the high court's next test on the issue.
Harvard said it was disappointed by the Justice Department's position.
A university statement said the school "will continue to vigorously defend the legal right
of every college and university to consider race" in college admissions.
The statement added that the Supreme Court has upheld that legal right for more than
40 years.
The university said colleges and universities must have the freedom to create mixed communities.
It said such an environment is critical the learning experience of all students.
Sessions argued the school's use of a "personal rating," such as being a "good person" or
"likeability," may be biased against Asian-Americans.
He said the school admits that it scores Asian-Americans lower on "personal rating" than others seeking
admission.
In July, the Trump administration cancelled a measure that ordered universities to consider
race in their admissions process to make the schools more racially mixed.
That order was left over from the last administration of President Barack Obama.
I'm Caty Weaver.
The enduring defeat of ISIS remains a top priority for the United States.
The U.S.-led Global Coalition to Defeat ISIS is leading stabilization efforts that consolidate
military gains, restore basic essential services, and enable Syrians to voluntarily and safely
return to their homes in Raqqa and other former ISIS strongholds.
Assistance includes explosive hazard and rubble removal, providing clean water, rehabilitating
electricity networks, and other basic necessities.
Since April, the United States has elicited approximately $300 million in contributions
and pledges from Coalition partners to support immediate stabilization and early recovery
initiatives in areas liberated from ISIS in northeast Syria, including a generous contribution
of $100 million by Saudi Arabia and $50 million by the United Arab Emirates.
As a result of these generous contributions and other factors, State Department Spokesperson
Heather Nauert announced, "the U.S. will redirect 230 million dollars in stabilization
funds for Syria which have been under review."
"This decision does not represent any lessening of U.S. commitment to our strategic goals
in Syria," stressed Ms. Nauert.
President Donald Trump has made clear that the U.S. is prepared to remain in Syria until
the enduring defeat of ISIS, and the U.S. remains focused on ensuring the withdrawal
of Iranian forces and their proxies.
"We believe," said Ms. Nauert, "that neither of these events will happen without
irreversible progress toward a political resolution of the conflict in accordance with UN Security
Council Resolution 2254."
This decision does not affect U.S. humanitarian assistance.
The United States is the largest single country humanitarian donor for the Syria response,
providing more than $8.6 billion in humanitarian assistance since the start of the crisis for
those displaced inside Syria and the region.
The U.S. will also continue to work with its international partners towards the achievement
of a peaceful resolution of the Syrian conflict under an UN-led political process.
The Syrian people deserve a country free of war, human rights abuses, and terrorism.
For more infomation >> WTAJ News at Noon - Duration: 29:35. 
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