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Novel 3D imaging technology makes fluorescence microscopy more efficient

Novel 3D imaging technology makes fluorescence microscopy more efficient

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HKU Biomedical Engineering develops novel 3D imaging technology to make fluorescence microscopy more efficient and push the boundaries of living cells research

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Credit: @The University of Hong Kong

Scientists have been using fluorescence microscopy to study the inner workings of biological cells and organisms for decades. However, many of these platforms are often too slow to follow the biological action in 3D; and too damaging to the living biological specimens with strong light illumination.

To address these challenges, a research team led by Dr Kevin Tsia, Associate Professor of the Department of Electrical and Electronic Engineering and Programme Director of Bachelor of Engineering in Biomedical Engineering of the University of Hong Kong (HKU), developed a new optical imaging technology – Coded Light-sheet Array Microscopy (CLAM) – which can perform 3D imaging at high speed, and is power efficient and gentle to preserve the living specimens during scanning at a level that is not achieved by existing technologies.

This advanced imaging technology was recently published in Light: Science & Applications. An US patent application has been filed for the innovation.

“CLAM allows 3D fluorescence imaging at high frame rate comparable to state-of-the-art technology (~10’s volumes per second). More importantly, it is much more power efficient, being over 1,000 times gentler than the standard 3D microscopes widely used in scientific laboratories, which greatly reduces the damage done to living specimens during scanning,” explained Dr Tsia.

Existing 3D biological microscopy platforms are slow because the entire volume of the specimen has to be sequentially scanned and imaged point-by-point, line-by-line or plane-by-plane. In these platforms, a single 3D snapshot requires repeated illumination on the specimen. The specimens are often illuminated for thousands to million times more intense than the sunlight. It is likely to damage the specimen itself, thus is not favorable for long-term biological imaging for diverse applications like anatomical science, developmental biology and neuroscience.

Moreover, these platforms often quickly exhaust the limited fluorescence “budget” – a fundamental constraint that fluorescent light can only be generated upon illumination for a limited period before it permanently fades out in a process called “photo-bleaching”, which sets a limit to how many image acquisitions can be performed on a sample.

“Repeated illumination on the specimen not only accelerates photo-bleaching, but also generates excessive fluorescence light that does not eventually form the final image. Hence, the fluorescence “budget” is largely wasted in these imaging platforms,” Dr Tsia added.

The heart of CLAM is transforming a single laser beam into a high-density array of “light-sheets” with the use of a pair of parallel mirrors, to spread over a large area of the specimen as fluorescence excitation.

“The image within the entire 3D volume is captured simultaneously (i.e. parallelized), without the need to scan the specimen point-by-point or line-by-line or plane-by-plane as required by other techniques. Such 3D parallelization in CLAM leads to a very gentle and efficient 3D fluorescence imaging without sacrificing sensitivity and speed,” as pointed out by Dr Yuxuan Ren, a postdoctoral researcher of the work. CLAM also outperforms the common 3D fluorescence imaging methods in reducing the effect of photo-bleaching.

To preserve the image resolution and quality in CLAM, the team turned to Code Division Multiplexing (CDM), an image encoding technique which is widely used in telecommunication for sending multiple signals simultaneously.

“This encoding technique allows us to use a 2D image sensor to capture and digitally reconstruct all image stacks in 3D simultaneously. CDM has never been used in 3D imaging before. We adopted the technology, which became a success,” explained by Dr Queenie Lai, another postdoctoral researcher who developed the system.

As a proof-of-concept demonstration, the team applied CLAM to capture 3D videos of fast microparticle flow in a microfluidic chip at a volume rate of over 10 volumes per second comparable to state-of-the-art technology.

“CLAM has no fundamental limitation in imaging speed. The only constraint is from the speed of the detector employed in the system, i.e. the camera for taking snapshots. As high-speed camera technology continually advances, CLAM can always challenge its limit to attain an even higher speed in scanning,” highlighted by Dr Jianglai Wu, the postdoctoral research who initiated the work.

The team has taken a step further to combine CLAM with HKU LKS Faculty of Medicine’s newly developed tissue clearing technology to perform 3D visualization of mouse glomeruli and intestine blood vasculature in high frame-rate.

“We anticipate that this combined technique can be extended to large-scale 3D histopathological investigation of archival biological samples, like mapping the cellular organization in brain for neuroscience research.” Dr Tsia said.

“Since CLAM imaging is significantly gentler than all other methods, it uniquely favours long term and continuous ‘surveillance’ of biological specimen in their living form. This could potentially impact our fundamental understanding in many aspects of cell biology, e.g. to continuously track how an animal embryo develops into its adult form; to monitor in real-time how the cells/organisms get infected by bacteria or viruses; to see how the cancer cells are killed by drugs, and other challenging tasks unachievable by existing technologies today,” Dr Tsia added.

CLAM can be adapted to many current microscope systems with minimal hardware or software modification. Taking advantage of this, the team is planning to further upgrade the current CLAM system for research in cell biology, animal and plant developmental biology.

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This project is an interdisciplinary collaboration between HKU Faculty of Engineering and LKS Faculty of Medicine. It was funded by HKSAR Research Grants Council, Innovation and Technology Support Program, the University Development Funds of the University of Hong Kong and the Natural Science Foundation of China.

For images and videos download please click here.

Details of the paper:

Parallelized volumetric fluorescence microscopy with a reconfigurable coded incoherent light-sheet array
Yu-Xuan Ren, Jianglai Wu, Queenie T. K. Lai, Hei Ming Lai, Dickson M. D. Siu, Wutian Wu, Kenneth K. Y. Wong & Kevin K. Tsia
Light: Science & Applications volume 9, Article number: 8 (2020)
https://www.nature.com/articles/s41377-020-0245-8

Media Contact
Celia Lee
leecelia@hku.hk

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https://www.hku.hk/press/news_detail_20876.html

Related Journal Article

http://dx.doi.org/10.1038/s41377-020-0245-8

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The Coming Of The Police State In America

The Coming Of The Police State In America

Authored by Jeffrey Tucker via The Epoch Times,

The National Guard and the State Police are now…

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The Coming Of The Police State In America

Authored by Jeffrey Tucker via The Epoch Times,

The National Guard and the State Police are now patrolling the New York City subway system in an attempt to do something about the explosion of crime. As part of this, there are bag checks and new surveillance of all passengers. No legislation, no debate, just an edict from the mayor.

Many citizens who rely on this system for transportation might welcome this. It’s a city of strict gun control, and no one knows for sure if they have the right to defend themselves. Merchants have been harassed and even arrested for trying to stop looting and pillaging in their own shops.

The message has been sent: Only the police can do this job. Whether they do it or not is another matter.

Things on the subway system have gotten crazy. If you know it well, you can manage to travel safely, but visitors to the city who take the wrong train at the wrong time are taking grave risks.

In actual fact, it’s guaranteed that this will only end in confiscating knives and other things that people carry in order to protect themselves while leaving the actual criminals even more free to prey on citizens.

The law-abiding will suffer and the criminals will grow more numerous. It will not end well.

When you step back from the details, what we have is the dawning of a genuine police state in the United States. It only starts in New York City. Where is the Guard going to be deployed next? Anywhere is possible.

If the crime is bad enough, citizens will welcome it. It must have been this way in most times and places that when the police state arrives, the people cheer.

We will all have our own stories of how this came to be. Some might begin with the passage of the Patriot Act and the establishment of the Department of Homeland Security in 2001. Some will focus on gun control and the taking away of citizens’ rights to defend themselves.

My own version of events is closer in time. It began four years ago this month with lockdowns. That’s what shattered the capacity of civil society to function in the United States. Everything that has happened since follows like one domino tumbling after another.

It goes like this:

1) lockdown,

2) loss of moral compass and spreading of loneliness and nihilism,

3) rioting resulting from citizen frustration, 4) police absent because of ideological hectoring,

5) a rise in uncontrolled immigration/refugees,

6) an epidemic of ill health from substance abuse and otherwise,

7) businesses flee the city

8) cities fall into decay, and that results in

9) more surveillance and police state.

The 10th stage is the sacking of liberty and civilization itself.

It doesn’t fall out this way at every point in history, but this seems like a solid outline of what happened in this case. Four years is a very short period of time to see all of this unfold. But it is a fact that New York City was more-or-less civilized only four years ago. No one could have predicted that it would come to this so quickly.

But once the lockdowns happened, all bets were off. Here we had a policy that most directly trampled on all freedoms that we had taken for granted. Schools, businesses, and churches were slammed shut, with various levels of enforcement. The entire workforce was divided between essential and nonessential, and there was widespread confusion about who precisely was in charge of designating and enforcing this.

It felt like martial law at the time, as if all normal civilian law had been displaced by something else. That something had to do with public health, but there was clearly more going on, because suddenly our social media posts were censored and we were being asked to do things that made no sense, such as mask up for a virus that evaded mask protection and walk in only one direction in grocery aisles.

Vast amounts of the white-collar workforce stayed home—and their kids, too—until it became too much to bear. The city became a ghost town. Most U.S. cities were the same.

As the months of disaster rolled on, the captives were let out of their houses for the summer in order to protest racism but no other reason. As a way of excusing this, the same public health authorities said that racism was a virus as bad as COVID-19, so therefore it was permitted.

The protests had turned to riots in many cities, and the police were being defunded and discouraged to do anything about the problem. Citizens watched in horror as downtowns burned and drug-crazed freaks took over whole sections of cities. It was like every standard of decency had been zapped out of an entire swath of the population.

Meanwhile, large checks were arriving in people’s bank accounts, defying every normal economic expectation. How could people not be working and get their bank accounts more flush with cash than ever? There was a new law that didn’t even require that people pay rent. How weird was that? Even student loans didn’t need to be paid.

By the fall, recess from lockdown was over and everyone was told to go home again. But this time they had a job to do: They were supposed to vote. Not at the polling places, because going there would only spread germs, or so the media said. When the voting results finally came in, it was the absentee ballots that swung the election in favor of the opposition party that actually wanted more lockdowns and eventually pushed vaccine mandates on the whole population.

The new party in control took note of the large population movements out of cities and states that they controlled. This would have a large effect on voting patterns in the future. But they had a plan. They would open the borders to millions of people in the guise of caring for refugees. These new warm bodies would become voters in time and certainly count on the census when it came time to reapportion political power.

Meanwhile, the native population had begun to swim in ill health from substance abuse, widespread depression, and demoralization, plus vaccine injury. This increased dependency on the very institutions that had caused the problem in the first place: the medical/scientific establishment.

The rise of crime drove the small businesses out of the city. They had barely survived the lockdowns, but they certainly could not survive the crime epidemic. This undermined the tax base of the city and allowed the criminals to take further control.

The same cities became sanctuaries for the waves of migrants sacking the country, and partisan mayors actually used tax dollars to house these invaders in high-end hotels in the name of having compassion for the stranger. Citizens were pushed out to make way for rampaging migrant hordes, as incredible as this seems.

But with that, of course, crime rose ever further, inciting citizen anger and providing a pretext to bring in the police state in the form of the National Guard, now tasked with cracking down on crime in the transportation system.

What’s the next step? It’s probably already here: mass surveillance and censorship, plus ever-expanding police power. This will be accompanied by further population movements, as those with the means to do so flee the city and even the country and leave it for everyone else to suffer.

As I tell the story, all of this seems inevitable. It is not. It could have been stopped at any point. A wise and prudent political leadership could have admitted the error from the beginning and called on the country to rediscover freedom, decency, and the difference between right and wrong. But ego and pride stopped that from happening, and we are left with the consequences.

The government grows ever bigger and civil society ever less capable of managing itself in large urban centers. Disaster is unfolding in real time, mitigated only by a rising stock market and a financial system that has yet to fall apart completely.

Are we at the middle stages of total collapse, or at the point where the population and people in leadership positions wise up and decide to put an end to the downward slide? It’s hard to know. But this much we do know: There is a growing pocket of resistance out there that is fed up and refuses to sit by and watch this great country be sacked and taken over by everything it was set up to prevent.

Tyler Durden Sat, 03/09/2024 - 16:20

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Low Iron Levels In Blood Could Trigger Long COVID: Study

Low Iron Levels In Blood Could Trigger Long COVID: Study

Authored by Amie Dahnke via The Epoch Times (emphasis ours),

People with inadequate…

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Low Iron Levels In Blood Could Trigger Long COVID: Study

Authored by Amie Dahnke via The Epoch Times (emphasis ours),

People with inadequate iron levels in their blood due to a COVID-19 infection could be at greater risk of long COVID.

(Shutterstock)

A new study indicates that problems with iron levels in the bloodstream likely trigger chronic inflammation and other conditions associated with the post-COVID phenomenon. The findings, published on March 1 in Nature Immunology, could offer new ways to treat or prevent the condition.

Long COVID Patients Have Low Iron Levels

Researchers at the University of Cambridge pinpointed low iron as a potential link to long-COVID symptoms thanks to a study they initiated shortly after the start of the pandemic. They recruited people who tested positive for the virus to provide blood samples for analysis over a year, which allowed the researchers to look for post-infection changes in the blood. The researchers looked at 214 samples and found that 45 percent of patients reported symptoms of long COVID that lasted between three and 10 months.

In analyzing the blood samples, the research team noticed that people experiencing long COVID had low iron levels, contributing to anemia and low red blood cell production, just two weeks after they were diagnosed with COVID-19. This was true for patients regardless of age, sex, or the initial severity of their infection.

According to one of the study co-authors, the removal of iron from the bloodstream is a natural process and defense mechanism of the body.

But it can jeopardize a person’s recovery.

When the body has an infection, it responds by removing iron from the bloodstream. This protects us from potentially lethal bacteria that capture the iron in the bloodstream and grow rapidly. It’s an evolutionary response that redistributes iron in the body, and the blood plasma becomes an iron desert,” University of Oxford professor Hal Drakesmith said in a press release. “However, if this goes on for a long time, there is less iron for red blood cells, so oxygen is transported less efficiently affecting metabolism and energy production, and for white blood cells, which need iron to work properly. The protective mechanism ends up becoming a problem.”

The research team believes that consistently low iron levels could explain why individuals with long COVID continue to experience fatigue and difficulty exercising. As such, the researchers suggested iron supplementation to help regulate and prevent the often debilitating symptoms associated with long COVID.

It isn’t necessarily the case that individuals don’t have enough iron in their body, it’s just that it’s trapped in the wrong place,” Aimee Hanson, a postdoctoral researcher at the University of Cambridge who worked on the study, said in the press release. “What we need is a way to remobilize the iron and pull it back into the bloodstream, where it becomes more useful to the red blood cells.”

The research team pointed out that iron supplementation isn’t always straightforward. Achieving the right level of iron varies from person to person. Too much iron can cause stomach issues, ranging from constipation, nausea, and abdominal pain to gastritis and gastric lesions.

1 in 5 Still Affected by Long COVID

COVID-19 has affected nearly 40 percent of Americans, with one in five of those still suffering from symptoms of long COVID, according to the U.S. Centers for Disease Control and Prevention (CDC). Long COVID is marked by health issues that continue at least four weeks after an individual was initially diagnosed with COVID-19. Symptoms can last for days, weeks, months, or years and may include fatigue, cough or chest pain, headache, brain fog, depression or anxiety, digestive issues, and joint or muscle pain.

Tyler Durden Sat, 03/09/2024 - 12:50

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February Employment Situation

By Paul Gomme and Peter Rupert The establishment data from the BLS showed a 275,000 increase in payroll employment for February, outpacing the 230,000…

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By Paul Gomme and Peter Rupert

The establishment data from the BLS showed a 275,000 increase in payroll employment for February, outpacing the 230,000 average over the previous 12 months. The payroll data for January and December were revised down by a total of 167,000. The private sector added 223,000 new jobs, the largest gain since May of last year.

Temporary help services employment continues a steep decline after a sharp post-pandemic rise.

Average hours of work increased from 34.2 to 34.3. The increase, along with the 223,000 private employment increase led to a hefty increase in total hours of 5.6% at an annualized rate, also the largest increase since May of last year.

The establishment report, once again, beat “expectations;” the WSJ survey of economists was 198,000. Other than the downward revisions, mentioned above, another bit of negative news was a smallish increase in wage growth, from $34.52 to $34.57.

The household survey shows that the labor force increased 150,000, a drop in employment of 184,000 and an increase in the number of unemployed persons of 334,000. The labor force participation rate held steady at 62.5, the employment to population ratio decreased from 60.2 to 60.1 and the unemployment rate increased from 3.66 to 3.86. Remember that the unemployment rate is the number of unemployed relative to the labor force (the number employed plus the number unemployed). Consequently, the unemployment rate can go up if the number of unemployed rises holding fixed the labor force, or if the labor force shrinks holding the number unemployed unchanged. An increase in the unemployment rate is not necessarily a bad thing: it may reflect a strong labor market drawing “marginally attached” individuals from outside the labor force. Indeed, there was a 96,000 decline in those workers.

Earlier in the week, the BLS announced JOLTS (Job Openings and Labor Turnover Survey) data for January. There isn’t much to report here as the job openings changed little at 8.9 million, the number of hires and total separations were little changed at 5.7 million and 5.3 million, respectively.

As has been the case for the last couple of years, the number of job openings remains higher than the number of unemployed persons.

Also earlier in the week the BLS announced that productivity increased 3.2% in the 4th quarter with output rising 3.5% and hours of work rising 0.3%.

The bottom line is that the labor market continues its surprisingly (to some) strong performance, once again proving stronger than many had expected. This strength makes it difficult to justify any interest rate cuts soon, particularly given the recent inflation spike.

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